diff --git a/lib/galaxy/datatypes/annotation.py b/lib/galaxy/datatypes/annotation.py
index 9a0717b5218..d5dd97cde80 100644
--- a/lib/galaxy/datatypes/annotation.py
+++ b/lib/galaxy/datatypes/annotation.py
@@ -14,7 +14,7 @@ class SnapHmm(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "SNAP HMM model"
         else:
             dataset.peek = 'file does not exist'
diff --git a/lib/galaxy/datatypes/binary.py b/lib/galaxy/datatypes/binary.py
index 1d69cbba5fb..e3a99c931bb 100644
--- a/lib/galaxy/datatypes/binary.py
+++ b/lib/galaxy/datatypes/binary.py
@@ -1088,7 +1088,7 @@ class TwoBit(Binary):
             dataset.peek = "Binary TwoBit format nucleotide file"
             dataset.blurb = nice_size(dataset.get_size())
         else:
-            return super(TwoBit, self).set_peek(dataset, is_multi_byte)
+            return super(TwoBit, self).set_peek(dataset)
 
     def display_peek(self, dataset):
         try:
diff --git a/lib/galaxy/datatypes/blast.py b/lib/galaxy/datatypes/blast.py
index 107202610f7..480c1ef1d67 100644
--- a/lib/galaxy/datatypes/blast.py
+++ b/lib/galaxy/datatypes/blast.py
@@ -53,7 +53,7 @@ class BlastXml(GenericXml):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = 'NCBI Blast XML data'
         else:
             dataset.peek = 'file does not exist'
diff --git a/lib/galaxy/datatypes/constructive_solid_geometry.py b/lib/galaxy/datatypes/constructive_solid_geometry.py
index 40325ffa5a0..9a31979afb3 100644
--- a/lib/galaxy/datatypes/constructive_solid_geometry.py
+++ b/lib/galaxy/datatypes/constructive_solid_geometry.py
@@ -102,7 +102,7 @@ class Ply(object):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "Faces: %s, Vertices: %s" % (str(dataset.metadata.face), str(dataset.metadata.vertex))
         else:
             dataset.peek = 'File does not exist'
@@ -429,7 +429,7 @@ class Vtk(object):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = self.get_blurb(dataset)
         else:
             dataset.peek = 'File does not exist'
diff --git a/lib/galaxy/datatypes/data.py b/lib/galaxy/datatypes/data.py
index 1ae1b583f17..0931e2bd005 100644
--- a/lib/galaxy/datatypes/data.py
+++ b/lib/galaxy/datatypes/data.py
@@ -195,7 +195,12 @@ class Data(object):
     max_optional_metadata_filesize = property(get_max_optional_metadata_filesize, set_max_optional_metadata_filesize)
 
     def set_peek(self, dataset, is_multi_byte=False):
-        """Set the peek and blurb text"""
+        """
+        Set the peek and blurb text
+
+        :param is_multi_byte: deprecated
+        :type  is_multi_byte: bool
+        """
         if not dataset.dataset.purged:
             dataset.peek = ''
             dataset.blurb = 'data'
@@ -838,7 +843,7 @@ class Text(Data):
         """
         if not dataset.dataset.purged:
             # The file must exist on disk for the get_file_peek() method
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte, WIDTH=WIDTH, skipchars=skipchars, line_wrap=line_wrap)
+            dataset.peek = get_file_peek(dataset.file_name, WIDTH=WIDTH, skipchars=skipchars, line_wrap=line_wrap)
             if line_count is None:
                 # See if line_count is stored in the metadata
                 if dataset.metadata.data_lines:
@@ -1046,7 +1051,10 @@ def get_test_fname(fname):
 
 def get_file_peek(file_name, is_multi_byte=False, WIDTH=256, LINE_COUNT=5, skipchars=None, line_wrap=True):
     """
-    Returns the first LINE_COUNT lines wrapped to WIDTH
+    Returns the first LINE_COUNT lines wrapped to WIDTH.
+
+    :param is_multi_byte: deprecated
+    :type  is_multi_byte: bool
 
     >>> fname = get_test_fname('4.bed')
     >>> get_file_peek(fname, LINE_COUNT=1)
@@ -1061,20 +1069,12 @@ def get_file_peek(file_name, is_multi_byte=False, WIDTH=256, LINE_COUNT=5, skipc
         skipchars = []
     lines = []
     count = 0
-    file_type = None
-    data_checked = False
     with compression_utils.get_fileobj(file_name, "U") as temp:
         while count < LINE_COUNT:
-            line = temp.readline(WIDTH)
-            if line and not is_multi_byte and not data_checked:
-                # See if we have a compressed or binary file
-                for char in line:
-                    if ord(char) > 128:
-                        file_type = 'binary'
-                        break
-                data_checked = True
-                if file_type == 'binary':
-                    break
+            try:
+                line = temp.readline(WIDTH)
+            except UnicodeDecodeError:
+                return "binary file"
             if not line_wrap:
                 if line.endswith('\n'):
                     line = line[:-1]
@@ -1091,11 +1091,4 @@ def get_file_peek(file_name, is_multi_byte=False, WIDTH=256, LINE_COUNT=5, skipc
             if not skip_line:
                 lines.append(line)
                 count += 1
-    if file_type == 'binary':
-        text = "%s file" % file_type
-    else:
-        try:
-            text = util.unicodify('\n'.join(lines))
-        except UnicodeDecodeError:
-            text = "binary/unknown file"
-    return text
+    return '\n'.join(lines)
diff --git a/lib/galaxy/datatypes/graph.py b/lib/galaxy/datatypes/graph.py
index cb50fb81d29..e8448fd155e 100644
--- a/lib/galaxy/datatypes/graph.py
+++ b/lib/galaxy/datatypes/graph.py
@@ -27,7 +27,7 @@ class Xgmml(xml.GenericXml):
         Set the peek and blurb text
         """
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'XGMML data'
         else:
             dataset.peek = 'file does not exist'
@@ -73,7 +73,7 @@ class Sif(tabular.Tabular):
         Set the peek and blurb text
         """
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'SIF data'
         else:
             dataset.peek = 'file does not exist'
diff --git a/lib/galaxy/datatypes/images.py b/lib/galaxy/datatypes/images.py
index 6c7e457a9ee..46659607d41 100644
--- a/lib/galaxy/datatypes/images.py
+++ b/lib/galaxy/datatypes/images.py
@@ -7,7 +7,6 @@ import zipfile
 from six.moves.urllib.parse import quote_plus
 
 from galaxy.datatypes.binary import Binary
-from galaxy.datatypes.sniff import get_headers
 from galaxy.datatypes.text import Html as HtmlFromText
 from galaxy.util import nice_size
 from galaxy.util.image_util import check_image_type
@@ -160,14 +159,8 @@ class Pdf(Image):
 
     def sniff(self, filename):
         """Determine if the file is in pdf format."""
-        headers = get_headers(filename, None, 1)
-        try:
-            if headers[0][0].startswith("%PDF"):
-                return True
-            else:
-                return False
-        except IndexError:
-            return False
+        with open(filename, 'rb') as fh:
+            return fh.read(4) == b"%PDF"
 
 
 Binary.register_sniffable_binary_format("pdf", "pdf", Pdf)
diff --git a/lib/galaxy/datatypes/molecules.py b/lib/galaxy/datatypes/molecules.py
index e7ee4734804..c3e00f33229 100644
--- a/lib/galaxy/datatypes/molecules.py
+++ b/lib/galaxy/datatypes/molecules.py
@@ -61,12 +61,11 @@ class GenericMolFile(data.Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
             if (dataset.metadata.number_of_molecules == 1):
                 dataset.blurb = "1 molecule"
             else:
                 dataset.blurb = "%s molecules" % dataset.metadata.number_of_molecules
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
         else:
             dataset.peek = 'file does not exist'
             dataset.blurb = 'file purged from disk'
@@ -471,7 +470,7 @@ class PHAR(GenericMolFile):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "pharmacophore"
         else:
             dataset.peek = 'file does not exist'
@@ -524,7 +523,7 @@ class PDB(GenericMolFile):
         if not dataset.dataset.purged:
             atom_numbers = count_special_lines("^ATOM", dataset.file_name)
             hetatm_numbers = count_special_lines("^HETATM", dataset.file_name)
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "%s atoms and %s HET-atoms" % (atom_numbers, hetatm_numbers)
         else:
             dataset.peek = 'file does not exist'
@@ -575,7 +574,7 @@ class PDBQT(GenericMolFile):
         if not dataset.dataset.purged:
             root_numbers = count_special_lines("^ROOT", dataset.file_name)
             branch_numbers = count_special_lines("^BRANCH", dataset.file_name)
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "%s roots and %s branches" % (root_numbers, branch_numbers)
         else:
             dataset.peek = 'file does not exist'
@@ -587,7 +586,7 @@ class grd(data.Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "grids for docking"
         else:
             dataset.peek = 'file does not exist'
@@ -621,12 +620,11 @@ class InChI(Tabular):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
             if (dataset.metadata.number_of_molecules == 1):
                 dataset.blurb = "1 molecule"
             else:
                 dataset.blurb = "%s molecules" % dataset.metadata.number_of_molecules
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
         else:
             dataset.peek = 'file does not exist'
             dataset.blurb = 'file purged from disk'
@@ -666,12 +664,11 @@ class SMILES(Tabular):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
             if dataset.metadata.number_of_molecules == 1:
                 dataset.blurb = "1 molecule"
             else:
                 dataset.blurb = "%s molecules" % dataset.metadata.number_of_molecules
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
         else:
             dataset.peek = 'file does not exist'
             dataset.blurb = 'file purged from disk'
@@ -727,12 +724,11 @@ class CML(GenericXml):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
             if (dataset.metadata.number_of_molecules == 1):
                 dataset.blurb = "1 molecule"
             else:
                 dataset.blurb = "%s molecules" % dataset.metadata.number_of_molecules
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
         else:
             dataset.peek = 'file does not exist'
             dataset.blurb = 'file purged from disk'
diff --git a/lib/galaxy/datatypes/msa.py b/lib/galaxy/datatypes/msa.py
index cc26438ceca..3985ef95488 100644
--- a/lib/galaxy/datatypes/msa.py
+++ b/lib/galaxy/datatypes/msa.py
@@ -17,7 +17,7 @@ class Hmmer(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "HMMER Database"
         else:
             dataset.peek = 'file does not exist'
@@ -104,12 +104,11 @@ class Stockholm_1_0(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
             if (dataset.metadata.number_of_models == 1):
                 dataset.blurb = "1 alignment"
             else:
                 dataset.blurb = "%s alignments" % dataset.metadata.number_of_models
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
         else:
             dataset.peek = 'file does not exist'
             dataset.blurb = 'file purged from disc'
@@ -187,12 +186,11 @@ class MauveXmfa(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
             if (dataset.metadata.number_of_models == 1):
                 dataset.blurb = "1 alignment"
             else:
                 dataset.blurb = "%s alignments" % dataset.metadata.number_of_models
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
         else:
             dataset.peek = 'file does not exist'
             dataset.blurb = 'file purged from disc'
diff --git a/lib/galaxy/datatypes/plant_tribes.py b/lib/galaxy/datatypes/plant_tribes.py
index d275e1aedf1..983600a86b9 100644
--- a/lib/galaxy/datatypes/plant_tribes.py
+++ b/lib/galaxy/datatypes/plant_tribes.py
@@ -23,7 +23,7 @@ class Smat(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "ESTScan scores matrices"
         else:
             dataset.peek = 'file does not exist'
@@ -125,7 +125,7 @@ class PlantTribesKsComponents(Tabular):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             if (dataset.metadata.number_comp == 1):
                 dataset.blurb = "1 significant component"
             else:
@@ -159,7 +159,7 @@ class PlantTribesOrtho(PlantTribes):
     file_ext = "ptortho"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesOrtho, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesOrtho, self).set_peek(dataset)
         dataset.blurb = "Proteins orthogroup fasta files: %d items" % dataset.metadata.num_files
 
 
@@ -171,7 +171,7 @@ class PlantTribesOrthoCodingSequence(PlantTribes):
     file_ext = "ptorthocs"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesOrthoCodingSequence, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesOrthoCodingSequence, self).set_peek(dataset)
         dataset.blurb = "Protein and coding sequences orthogroup fasta files: %d items" % dataset.metadata.num_files
 
 
@@ -182,7 +182,7 @@ class PlantTribesTargetedGeneFamilies(PlantTribes):
     file_ext = "pttgf"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesTargetedGeneFamilies, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesTargetedGeneFamilies, self).set_peek(dataset)
         dataset.blurb = "Targeted gene families"
 
 
@@ -194,7 +194,7 @@ class PlantTribesPhylogeneticTree(PlantTribes):
     file_ext = "pttree"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesPhylogeneticTree, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesPhylogeneticTree, self).set_peek(dataset)
         dataset.blurb = "Phylogenetic trees: %d items" % dataset.metadata.num_files
 
 
@@ -205,7 +205,7 @@ class PlantTribesPhylip(PlantTribes):
     file_ext = "ptphylip"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesPhylip, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesPhylip, self).set_peek(dataset)
         dataset.blurb = "Orthogroup phylip multiple sequence alignments: %d items" % dataset.metadata.num_files
 
 
@@ -216,7 +216,7 @@ class PlantTribesMultipleSequenceAlignment(PlantTribes):
     file_ext = "ptalign"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesMultipleSequenceAlignment, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesMultipleSequenceAlignment, self).set_peek(dataset)
         dataset.blurb = "Proteins orthogroup alignments: %d items" % dataset.metadata.num_files
 
 
@@ -227,7 +227,7 @@ class PlantTribesMultipleSequenceAlignmentCodonAlignment(PlantTribes):
     file_ext = "ptalignca"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesMultipleSequenceAlignmentCodonAlignment, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesMultipleSequenceAlignmentCodonAlignment, self).set_peek(dataset)
         dataset.blurb = "Protein and coding sequences orthogroup alignments: %d items" % dataset.metadata.num_files
 
 
@@ -238,7 +238,7 @@ class PlantTribesMultipleSequenceAlignmentTrimmed(PlantTribes):
     file_ext = "ptaligntrimmed"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesMultipleSequenceAlignmentTrimmed, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesMultipleSequenceAlignmentTrimmed, self).set_peek(dataset)
         dataset.blurb = "Trimmed proteins orthogroup alignments: %d items" % dataset.metadata.num_files
 
 
@@ -249,7 +249,7 @@ class PlantTribesMultipleSequenceAlignmentTrimmedCodonAlignment(PlantTribes):
     file_ext = "ptaligntrimmedca"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesMultipleSequenceAlignmentTrimmedCodonAlignment, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesMultipleSequenceAlignmentTrimmedCodonAlignment, self).set_peek(dataset)
         dataset.blurb = "Trimmed protein and coding sequences orthogroup alignments: %d items" % dataset.metadata.num_files
 
 
@@ -260,7 +260,7 @@ class PlantTribesMultipleSequenceAlignmentFiltered(PlantTribes):
     file_ext = "ptalignfiltered"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesMultipleSequenceAlignmentFiltered, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesMultipleSequenceAlignmentFiltered, self).set_peek(dataset)
         dataset.blurb = "Filtered proteins orthogroup alignments: %d items" % dataset.metadata.num_files
 
 
@@ -271,5 +271,5 @@ class PlantTribesMultipleSequenceAlignmentFilteredCodonAlignment(PlantTribes):
     file_ext = "ptalignfilteredca"
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(PlantTribesMultipleSequenceAlignmentFilteredCodonAlignment, self).set_peek(dataset, is_multi_byte=is_multi_byte)
+        super(PlantTribesMultipleSequenceAlignmentFilteredCodonAlignment, self).set_peek(dataset)
         dataset.blurb = "Filtered protein and coding sequences orthogroup alignments: %d items" % dataset.metadata.num_files
diff --git a/lib/galaxy/datatypes/proteomics.py b/lib/galaxy/datatypes/proteomics.py
index 27e923c2b3b..932e0fe90fa 100644
--- a/lib/galaxy/datatypes/proteomics.py
+++ b/lib/galaxy/datatypes/proteomics.py
@@ -114,7 +114,7 @@ class ProteomicsXml(GenericXml):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = self.blurb
         else:
             dataset.peek = 'file does not exist'
@@ -221,7 +221,7 @@ class Mgf(Text):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'mgf Mascot Generic Format'
         else:
             dataset.peek = 'file does not exist'
@@ -249,7 +249,7 @@ class MascotDat(Text):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'mascotdat Mascot Search Results'
         else:
             dataset.peek = 'file does not exist'
@@ -334,7 +334,7 @@ class SPLibNoIndex(Text):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'Spectral Library without index files'
         else:
             dataset.peek = 'file does not exist'
@@ -374,7 +374,7 @@ class SPLib(Msp):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'splib Spectral Library Format'
         else:
             dataset.peek = 'file does not exist'
diff --git a/lib/galaxy/datatypes/registry.py b/lib/galaxy/datatypes/registry.py
index 4fd441e5863..08ea3d4f544 100644
--- a/lib/galaxy/datatypes/registry.py
+++ b/lib/galaxy/datatypes/registry.py
@@ -314,13 +314,14 @@ class Registry(object):
         def append_to_sniff_order():
             # Just in case any supported data types are not included in the config's sniff_order section.
             for ext, datatype in self.datatypes_by_extension.items():
-                included = False
-                for atype in self.sniff_order:
-                    if isinstance(atype, datatype.__class__):
-                        included = True
-                        break
-                if not included:
-                    self.sniff_order.append(datatype)
+                if hasattr(datatype, 'sniff'):
+                    included = False
+                    for atype in self.sniff_order:
+                        if isinstance(atype, datatype.__class__):
+                            included = True
+                            break
+                    if not included:
+                        self.sniff_order.append(datatype)
         append_to_sniff_order()
 
     def _load_build_sites(self, root):
diff --git a/lib/galaxy/datatypes/sequence.py b/lib/galaxy/datatypes/sequence.py
index ec47b34235d..fe521fb49b5 100644
--- a/lib/galaxy/datatypes/sequence.py
+++ b/lib/galaxy/datatypes/sequence.py
@@ -61,7 +61,7 @@ class SequenceSplitLocations(data.Text):
             try:
                 parsed_data = json.load(open(dataset.file_name))
                 # dataset.peek = json.dumps(data, sort_keys=True, indent=4)
-                dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+                dataset.peek = data.get_file_peek(dataset.file_name)
                 dataset.blurb = '%d sections' % len(parsed_data['sections'])
             except Exception:
                 dataset.peek = 'Not FQTOC file'
@@ -112,7 +112,7 @@ class Sequence(data.Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             if dataset.metadata.sequences:
                 dataset.blurb = "%s sequences" % util.commaify(str(dataset.metadata.sequences))
             else:
@@ -861,7 +861,7 @@ class Maf(Alignment):
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
             # The file must exist on disk for the get_file_peek() method
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             if dataset.metadata.blocks:
                 dataset.blurb = "%s blocks" % util.commaify(str(dataset.metadata.blocks))
             else:
diff --git a/lib/galaxy/datatypes/sniff.py b/lib/galaxy/datatypes/sniff.py
index 970beefa63d..e8de38168a3 100644
--- a/lib/galaxy/datatypes/sniff.py
+++ b/lib/galaxy/datatypes/sniff.py
@@ -20,7 +20,6 @@ from galaxy.datatypes.binary import Binary
 from galaxy.util import (
     compression_utils,
     multi_byte,
-    unicodify
 )
 from galaxy.util.checkers import (
     check_binary,
@@ -204,17 +203,11 @@ def convert_newlines_sep2tabs(fname, in_place=True, patt="\\s+", tmp_dir=None, t
         return (i + 1, temp_name)
 
 
-def iter_headers(fname, sep, count=60, is_multi_byte=False, comment_designator=None):
+def iter_headers(fname, sep, count=60, comment_designator=None):
     with compression_utils.get_fileobj(fname) as in_file:
         idx = 0
         for line in in_file:
             line = line.rstrip('\n\r')
-            if is_multi_byte:
-                # TODO: fix this - sep is never found in line
-                line = unicodify(line, 'utf-8')
-                sep = sep.encode('utf-8')
-                if comment_designator is not None and comment_designator != '':
-                    comment_designator = comment_designator.encode('utf-8')
             if comment_designator is not None and comment_designator != '' and line.startswith(comment_designator):
                 continue
             yield line.split(sep)
@@ -223,22 +216,22 @@ def iter_headers(fname, sep, count=60, is_multi_byte=False, comment_designator=N
                 break
 
 
-def get_headers(fname, sep, count=60, is_multi_byte=False, comment_designator=None):
+def get_headers(fname, sep, count=60, comment_designator=None):
     """
     Returns a list with the first 'count' lines split by 'sep', ignoring lines
     starting with 'comment_designator'
 
     >>> fname = get_test_fname('complete.bed')
-    >>> get_headers(fname,'\\t')
-    [['chr7', '127475281', '127491632', 'NM_000230', '0', '+', '127486022', '127488767', '0', '3', '29,172,3225,', '0,10713,13126,'], ['chr7', '127486011', '127488900', 'D49487', '0', '+', '127486022', '127488767', '0', '2', '155,490,', '0,2399']]
+    >>> get_headers(fname,'\\t') == [['chr7', '127475281', '127491632', 'NM_000230', '0', '+', '127486022', '127488767', '0', '3', '29,172,3225,', '0,10713,13126,'], ['chr7', '127486011', '127488900', 'D49487', '0', '+', '127486022', '127488767', '0', '2', '155,490,', '0,2399']]
+    True
     >>> fname = get_test_fname('test.gff')
-    >>> get_headers(fname, '\\t', count=5, comment_designator='#')
-    [[''], ['chr7', 'bed2gff', 'AR', '26731313', '26731437', '.', '+', '.', 'score'], ['chr7', 'bed2gff', 'AR', '26731491', '26731536', '.', '+', '.', 'score'], ['chr7', 'bed2gff', 'AR', '26731541', '26731649', '.', '+', '.', 'score'], ['chr7', 'bed2gff', 'AR', '26731659', '26731841', '.', '+', '.', 'score']]
+    >>> get_headers(fname, '\\t', count=5, comment_designator='#') == [[''], ['chr7', 'bed2gff', 'AR', '26731313', '26731437', '.', '+', '.', 'score'], ['chr7', 'bed2gff', 'AR', '26731491', '26731536', '.', '+', '.', 'score'], ['chr7', 'bed2gff', 'AR', '26731541', '26731649', '.', '+', '.', 'score'], ['chr7', 'bed2gff', 'AR', '26731659', '26731841', '.', '+', '.', 'score']]
+    True
     """
-    return list(iter_headers(fname=fname, sep=sep, count=count, is_multi_byte=is_multi_byte, comment_designator=comment_designator))
+    return list(iter_headers(fname=fname, sep=sep, count=count, comment_designator=comment_designator))
 
 
-def is_column_based(fname, sep='\t', skip=0, is_multi_byte=False):
+def is_column_based(fname, sep='\t', skip=0):
     """
     Checks whether the file is column based with respect to a separator
     (defaults to tab separator).
@@ -266,7 +259,10 @@ def is_column_based(fname, sep='\t', skip=0, is_multi_byte=False):
     >>> is_column_based(fname)
     True
     """
-    headers = get_headers(fname, sep, is_multi_byte=is_multi_byte)
+    try:
+        headers = get_headers(fname, sep)
+    except UnicodeDecodeError:
+        return False
     count = 0
     if not headers:
         return False
@@ -284,7 +280,7 @@ def is_column_based(fname, sep='\t', skip=0, is_multi_byte=False):
     return True
 
 
-def guess_ext(fname, sniff_order, is_multi_byte=False):
+def guess_ext(fname, sniff_order):
     """
     Returns an extension that can be used in the datatype factory to
     generate a data for the 'fname' file
@@ -393,6 +389,9 @@ def guess_ext(fname, sniff_order, is_multi_byte=False):
     >>> fname = get_test_fname('biom2_sparse_otu_table_hdf5.biom')
     >>> guess_ext(fname, sniff_order)
     'biom2'
+    >>> fname = get_test_fname('454Score.pdf')
+    >>> guess_ext(fname, sniff_order)
+    'pdf'
     """
     file_ext = None
     for datatype in sniff_order:
@@ -414,28 +413,16 @@ def guess_ext(fname, sniff_order, is_multi_byte=False):
     # to tsv but it doesn't have a sniffer - is TSV was sniffed just check
     # if it is an okay tabular and use that instead.
     if file_ext == 'tsv':
-        if is_column_based(fname, '\t', 1, is_multi_byte=is_multi_byte):
+        if is_column_based(fname, '\t', 1):
             file_ext = 'tabular'
     if file_ext is not None:
         return file_ext
 
-    headers = get_headers(fname, None)
-    is_binary = False
-    if is_multi_byte:
-        is_binary = False
-    else:
-        for hdr in headers:
-            for char in hdr:
-                # old behavior had 'char' possibly having length > 1,
-                # need to determine when/if this occurs
-                is_binary = util.is_binary(char)
-                if is_binary:
-                    break
-            if is_binary:
-                break
-    if is_binary:
+    try:
+        get_headers(fname, None)
+    except UnicodeDecodeError:
         return 'data'  # default binary data type file extension
-    if is_column_based(fname, '\t', 1, is_multi_byte=is_multi_byte):
+    if is_column_based(fname, '\t', 1):
         return 'tabular'  # default tabular data type file extension
     return 'txt'  # default text data type file extension
 
@@ -489,14 +476,14 @@ def handle_compressed_file(filename, datatypes_registry, ext='auto'):
     return is_valid, ext
 
 
-def handle_uploaded_dataset_file(filename, datatypes_registry, ext='auto', is_multi_byte=False):
+def handle_uploaded_dataset_file(filename, datatypes_registry, ext='auto'):
     is_valid, ext = handle_compressed_file(filename, datatypes_registry, ext=ext)
 
     if not is_valid:
         raise InappropriateDatasetContentError('The compressed uploaded file contains inappropriate content.')
 
     if ext in AUTO_DETECT_EXTENSIONS:
-        ext = guess_ext(filename, sniff_order=datatypes_registry.sniff_order, is_multi_byte=is_multi_byte)
+        ext = guess_ext(filename, sniff_order=datatypes_registry.sniff_order)
 
     if check_binary(filename):
         if not Binary.is_ext_unsniffable(ext) and not datatypes_registry.get_datatype_by_extension(ext).sniff(filename):
diff --git a/lib/galaxy/datatypes/tabular.py b/lib/galaxy/datatypes/tabular.py
index 731ec358464..7f94565fb89 100644
--- a/lib/galaxy/datatypes/tabular.py
+++ b/lib/galaxy/datatypes/tabular.py
@@ -51,7 +51,7 @@ class TabularData(data.Text):
         raise NotImplementedError
 
     def set_peek(self, dataset, line_count=None, is_multi_byte=False, WIDTH=256, skipchars=None):
-        super(TabularData, self).set_peek(dataset, line_count=line_count, is_multi_byte=is_multi_byte, WIDTH=WIDTH, skipchars=skipchars, line_wrap=False)
+        super(TabularData, self).set_peek(dataset, line_count=line_count, WIDTH=WIDTH, skipchars=skipchars, line_wrap=False)
         if dataset.metadata.comment_lines:
             dataset.blurb = "%s, %s comments" % (dataset.blurb, util.commaify(str(dataset.metadata.comment_lines)))
 
@@ -825,7 +825,7 @@ class Eland(Tabular):
             - LANE, TILEm X, Y, INDEX, READ_NO, SEQ, QUAL, POSITION, *STRAND, FILT must be correct
             - We will only check that up to the first 5 alignments are correctly formatted.
         """
-        with compression_utils.get_fileobj(filename, gzip_only=True) as fh:
+        with compression_utils.get_fileobj(filename, compressed_formats=['gzip']) as fh:
             count = 0
             while True:
                 line = fh.readline()
diff --git a/lib/galaxy/datatypes/test/454Score.pdf b/lib/galaxy/datatypes/test/454Score.pdf
new file mode 100644
index 00000000000..1199be2305a
--- /dev/null
+++ b/lib/galaxy/datatypes/test/454Score.pdf
@@ -0,0 +1,545 @@
+%PDF-1.1
+%���ρ�\r
+1 0 obj
+<<
+/CreationDate (D:20080403110358)
+/ModDate (D:20080403110358)
+/Title (R Graphics Output)
+/Producer (R 2.6.2)
+/Creator (R)
+>>
+endobj
+2 0 obj
+<<
+/Type /Catalog
+/Pages 3 0 R
+>>
+endobj
+5 0 obj
+<<
+/Type /Font
+/Subtype /Type1
+/Name /F1
+/BaseFont /ZapfDingbats
+>>
+endobj
+6 0 obj
+<<
+/Type /Page
+/Parent 3 0 R
+/Contents 7 0 R
+/Resources 4 0 R
+>>
+endobj
+7 0 obj
+<<
+/Length 8 0 R
+>>
+stream
+q
+Q q 59.04 73.44 342.72 299.52 re W n
+0.000 0.000 0.000 RG
+2.25 w
+[] 0 d
+1 J
+1 j
+10.00 M
+73.40 149.79 m 86.76 149.79 l S
+0.75 w
+[ 3.00 5.00] 0 d
+80.08 100.85 m 80.08 149.79 l S
+80.08 296.61 m 80.08 263.98 l S
+0.75 w
+[] 0 d
+76.74 100.85 m 83.42 100.85 l S
+76.74 296.61 m 83.42 296.61 l S
+73.40 149.79 m
+86.76 149.79 l
+86.76 263.98 l
+73.40 263.98 l
+73.40 149.79 l
+S
+2.25 w
+[] 0 d
+90.11 280.30 m 103.47 280.30 l S
+0.75 w
+[ 3.00 5.00] 0 d
+96.79 263.98 m 96.79 280.30 l S
+96.79 296.61 m 96.79 296.61 l S
+0.75 w
+[] 0 d
+93.45 263.98 m 100.13 263.98 l S
+93.45 296.61 m 100.13 296.61 l S
+90.11 280.30 m
+103.47 280.30 l
+103.47 296.61 l
+90.11 296.61 l
+90.11 280.30 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 93.82 342.96 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+106.81 280.30 m 120.17 280.30 l S
+0.75 w
+[ 3.00 5.00] 0 d
+113.49 263.98 m 113.49 263.98 l S
+113.49 280.30 m 113.49 280.30 l S
+0.75 w
+[] 0 d
+110.15 263.98 m 116.83 263.98 l S
+110.15 280.30 m 116.83 280.30 l S
+106.81 263.98 m
+120.17 263.98 l
+120.17 280.30 l
+106.81 280.30 l
+106.81 263.98 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 110.53 179.82 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+123.51 247.67 m 136.87 247.67 l S
+0.75 w
+[ 3.00 5.00] 0 d
+130.19 247.67 m 130.19 247.67 l S
+130.19 247.67 m 130.19 247.67 l S
+0.75 w
+[] 0 d
+126.85 247.67 m 133.53 247.67 l S
+126.85 247.67 m 133.53 247.67 l S
+123.51 247.67 m
+136.87 247.67 l
+136.87 247.67 l
+123.51 247.67 l
+123.51 247.67 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 127.23 261.39 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+140.21 280.30 m 153.57 280.30 l S
+0.75 w
+[ 3.00 5.00] 0 d
+146.89 231.36 m 146.89 247.67 l S
+146.89 361.87 m 146.89 296.61 l S
+0.75 w
+[] 0 d
+143.55 231.36 m 150.23 231.36 l S
+143.55 361.87 m 150.23 361.87 l S
+140.21 247.67 m
+153.57 247.67 l
+153.57 296.61 l
+140.21 296.61 l
+140.21 247.67 l
+S
+2.25 w
+[] 0 d
+156.91 280.30 m 170.27 280.30 l S
+0.75 w
+[ 3.00 5.00] 0 d
+163.59 198.73 m 163.59 231.36 l S
+163.59 280.30 m 163.59 280.30 l S
+0.75 w
+[] 0 d
+160.25 198.73 m 166.93 198.73 l S
+160.25 280.30 m 166.93 280.30 l S
+156.91 231.36 m
+170.27 231.36 l
+170.27 280.30 l
+156.91 280.30 l
+156.91 231.36 l
+S
+2.25 w
+[] 0 d
+173.61 280.30 m 186.98 280.30 l S
+0.75 w
+[ 3.00 5.00] 0 d
+180.29 247.67 m 180.29 263.98 l S
+180.29 280.30 m 180.29 280.30 l S
+0.75 w
+[] 0 d
+176.95 247.67 m 183.64 247.67 l S
+176.95 280.30 m 183.64 280.30 l S
+173.61 263.98 m
+186.98 263.98 l
+186.98 280.30 l
+173.61 280.30 l
+173.61 263.98 l
+S
+2.25 w
+[] 0 d
+190.32 247.67 m 203.68 247.67 l S
+0.75 w
+[ 3.00 5.00] 0 d
+197.00 247.67 m 197.00 247.67 l S
+197.00 263.98 m 197.00 263.98 l S
+0.75 w
+[] 0 d
+193.66 247.67 m 200.34 247.67 l S
+193.66 263.98 m 200.34 263.98 l S
+190.32 247.67 m
+203.68 247.67 l
+203.68 263.98 l
+190.32 263.98 l
+190.32 247.67 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 194.03 294.02 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+207.02 263.98 m 220.38 263.98 l S
+0.75 w
+[ 3.00 5.00] 0 d
+213.70 247.67 m 213.70 247.67 l S
+213.70 263.98 m 213.70 263.98 l S
+0.75 w
+[] 0 d
+210.36 247.67 m 217.04 247.67 l S
+210.36 263.98 m 217.04 263.98 l S
+207.02 247.67 m
+220.38 247.67 l
+220.38 263.98 l
+207.02 263.98 l
+207.02 247.67 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 210.74 342.96 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+223.72 263.98 m 237.08 263.98 l S
+0.75 w
+[ 3.00 5.00] 0 d
+230.40 263.98 m 230.40 263.98 l S
+230.40 280.30 m 230.40 280.30 l S
+0.75 w
+[] 0 d
+227.06 263.98 m 233.74 263.98 l S
+227.06 280.30 m 233.74 280.30 l S
+223.72 263.98 m
+237.08 263.98 l
+237.08 280.30 l
+223.72 280.30 l
+223.72 263.98 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 227.44 163.51 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+240.42 280.30 m 253.78 280.30 l S
+0.75 w
+[ 3.00 5.00] 0 d
+247.10 263.98 m 247.10 263.98 l S
+247.10 280.30 m 247.10 280.30 l S
+0.75 w
+[] 0 d
+243.76 263.98 m 250.44 263.98 l S
+243.76 280.30 m 250.44 280.30 l S
+240.42 263.98 m
+253.78 263.98 l
+253.78 280.30 l
+240.42 280.30 l
+240.42 263.98 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 244.14 179.82 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+257.12 263.98 m 270.48 263.98 l S
+0.75 w
+[ 3.00 5.00] 0 d
+263.80 247.67 m 263.80 247.67 l S
+263.80 280.30 m 263.80 280.30 l S
+0.75 w
+[] 0 d
+260.46 247.67 m 267.14 247.67 l S
+260.46 280.30 m 267.14 280.30 l S
+257.12 247.67 m
+270.48 247.67 l
+270.48 280.30 l
+257.12 280.30 l
+257.12 247.67 l
+S
+2.25 w
+[] 0 d
+273.82 247.67 m 287.19 247.67 l S
+0.75 w
+[ 3.00 5.00] 0 d
+280.51 84.53 m 280.51 182.42 l S
+280.51 296.61 m 280.51 296.61 l S
+0.75 w
+[] 0 d
+277.16 84.53 m 283.85 84.53 l S
+277.16 296.61 m 283.85 296.61 l S
+273.82 182.42 m
+287.19 182.42 l
+287.19 296.61 l
+273.82 296.61 l
+273.82 182.42 l
+S
+2.25 w
+[] 0 d
+290.53 280.30 m 303.89 280.30 l S
+0.75 w
+[ 3.00 5.00] 0 d
+297.21 280.30 m 297.21 280.30 l S
+297.21 280.30 m 297.21 280.30 l S
+0.75 w
+[] 0 d
+293.87 280.30 m 300.55 280.30 l S
+293.87 280.30 m 300.55 280.30 l S
+290.53 280.30 m
+303.89 280.30 l
+303.89 280.30 l
+290.53 280.30 l
+290.53 280.30 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 294.25 294.02 Tm (l) Tj 0 Tr
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 294.25 228.76 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+307.23 263.98 m 320.59 263.98 l S
+0.75 w
+[ 3.00 5.00] 0 d
+313.91 247.67 m 313.91 247.67 l S
+313.91 280.30 m 313.91 280.30 l S
+0.75 w
+[] 0 d
+310.57 247.67 m 317.25 247.67 l S
+310.57 280.30 m 317.25 280.30 l S
+307.23 247.67 m
+320.59 247.67 l
+320.59 280.30 l
+307.23 280.30 l
+307.23 247.67 l
+S
+2.25 w
+[] 0 d
+323.93 231.36 m 337.29 231.36 l S
+0.75 w
+[ 3.00 5.00] 0 d
+330.61 198.73 m 330.61 215.04 l S
+330.61 231.36 m 330.61 231.36 l S
+0.75 w
+[] 0 d
+327.27 198.73 m 333.95 198.73 l S
+327.27 231.36 m 333.95 231.36 l S
+323.93 215.04 m
+337.29 215.04 l
+337.29 231.36 l
+323.93 231.36 l
+323.93 215.04 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 327.65 261.39 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+340.63 263.98 m 353.99 263.98 l S
+0.75 w
+[ 3.00 5.00] 0 d
+347.31 263.98 m 347.31 263.98 l S
+347.31 263.98 m 347.31 263.98 l S
+0.75 w
+[] 0 d
+343.97 263.98 m 350.65 263.98 l S
+343.97 263.98 m 350.65 263.98 l S
+340.63 263.98 m
+353.99 263.98 l
+353.99 263.98 l
+340.63 263.98 l
+340.63 263.98 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 344.35 179.82 Tm (l) Tj 0 Tr
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 344.35 277.70 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+357.33 263.98 m 370.69 263.98 l S
+0.75 w
+[ 3.00 5.00] 0 d
+364.01 247.67 m 364.01 247.67 l S
+364.01 280.30 m 364.01 280.30 l S
+0.75 w
+[] 0 d
+360.67 247.67 m 367.35 247.67 l S
+360.67 280.30 m 367.35 280.30 l S
+357.33 247.67 m
+370.69 247.67 l
+370.69 280.30 l
+357.33 280.30 l
+357.33 247.67 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 361.05 81.94 Tm (l) Tj 0 Tr
+2.25 w
+[] 0 d
+ET
+374.04 263.98 m 387.40 263.98 l S
+0.75 w
+[ 3.00 5.00] 0 d
+380.72 263.98 m 380.72 263.98 l S
+380.72 296.61 m 380.72 296.61 l S
+0.75 w
+[] 0 d
+377.38 263.98 m 384.06 263.98 l S
+377.38 296.61 m 384.06 296.61 l S
+374.04 263.98 m
+387.40 263.98 l
+387.40 296.61 l
+374.04 296.61 l
+374.04 263.98 l
+S
+BT
+/F1 1 Tf 1 Tr 7.48 0 0 7.48 377.75 163.51 Tm (l) Tj 0 Tr
+ET
+Q q
+0.000 0.000 0.000 RG
+0.75 w
+[] 0 d
+1 J
+1 j
+10.00 M
+59.04 133.47 m 59.04 296.61 l S
+59.04 133.47 m 51.84 133.47 l S
+59.04 215.04 m 51.84 215.04 l S
+59.04 296.61 m 51.84 296.61 l S
+BT
+0.000 0.000 0.000 rg
+/F2 1 Tf 0.00 12.00 -12.00 0.00 41.76 126.80 Tm (20) Tj
+/F2 1 Tf 0.00 12.00 -12.00 0.00 41.76 208.37 Tm (25) Tj
+/F2 1 Tf 0.00 12.00 -12.00 0.00 41.76 289.94 Tm (30) Tj
+ET
+Q q
+BT
+0.000 0.000 0.000 rg
+/F3 1 Tf 14.00 0.00 -0.00 14.00 147.76 397.45 Tm (boxplot of quality scores) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 130.36 18.72 Tm (position within read \(% of total length\)) Tj
+ET
+Q q
+0.000 0.000 0.000 RG
+0.75 w
+[] 0 d
+1 J
+1 j
+10.00 M
+59.04 73.44 m
+401.76 73.44 l
+401.76 372.96 l
+59.04 372.96 l
+59.04 73.44 l
+S
+63.38 73.44 m 380.72 73.44 l S
+63.38 73.44 m 63.38 66.24 l S
+80.08 73.44 m 80.08 66.24 l S
+96.79 73.44 m 96.79 66.24 l S
+113.49 73.44 m 113.49 66.24 l S
+130.19 73.44 m 130.19 66.24 l S
+146.89 73.44 m 146.89 66.24 l S
+163.59 73.44 m 163.59 66.24 l S
+180.29 73.44 m 180.29 66.24 l S
+197.00 73.44 m 197.00 66.24 l S
+213.70 73.44 m 213.70 66.24 l S
+230.40 73.44 m 230.40 66.24 l S
+247.10 73.44 m 247.10 66.24 l S
+263.80 73.44 m 263.80 66.24 l S
+280.51 73.44 m 280.51 66.24 l S
+297.21 73.44 m 297.21 66.24 l S
+313.91 73.44 m 313.91 66.24 l S
+330.61 73.44 m 330.61 66.24 l S
+347.31 73.44 m 347.31 66.24 l S
+364.01 73.44 m 364.01 66.24 l S
+380.72 73.44 m 380.72 66.24 l S
+BT
+0.000 0.000 0.000 rg
+/F2 1 Tf 12.00 0.00 -0.00 12.00 60.05 47.52 Tm (0) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 76.75 47.52 Tm (5) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 106.82 47.52 Tm (15) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 140.22 47.52 Tm (25) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 173.62 47.52 Tm (35) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 207.03 47.52 Tm (45) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 240.43 47.52 Tm (55) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 273.83 47.52 Tm (65) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 307.24 47.52 Tm (75) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 340.64 47.52 Tm (85) Tj
+/F2 1 Tf 12.00 0.00 -0.00 12.00 374.04 47.52 Tm (95) Tj
+ET
+Q
+endstream
+endobj
+8 0 obj
+8714
+endobj
+3 0 obj
+<<
+/Type /Pages
+/Kids [
+6 0 R
+]
+/Count 1
+/MediaBox [0 0 432 432]
+>>
+endobj
+4 0 obj
+<<
+/ProcSet [/PDF /Text]
+/Font << /F1 5 0 R /F2 10 0 R /F3 11 0 R >>
+/ExtGState << >>
+>>
+endobj
+9 0 obj
+<<
+/Type /Encoding
+/BaseEncoding /WinAnsiEncoding
+/Differences [ 45/minus 96/quoteleft
+144/dotlessi /grave /acute /circumflex /tilde /macron /breve /dotaccent
+/dieresis /.notdef /ring /cedilla /.notdef /hungarumlaut /ogonek /caron /space]
+>>
+endobj
+10 0 obj <<
+/Type /Font
+/Subtype /Type1
+/Name /F2
+/BaseFont /Helvetica
+/Encoding 9 0 R
+>> endobj
+11 0 obj <<
+/Type /Font
+/Subtype /Type1
+/Name /F3
+/BaseFont /Helvetica-Bold
+/Encoding 9 0 R
+>> endobj
+xref
+0 12
+0000000000 65535 f 
+0000000021 00000 n 
+0000000163 00000 n 
+0000009162 00000 n 
+0000009245 00000 n 
+0000000212 00000 n 
+0000000295 00000 n 
+0000000375 00000 n 
+0000009142 00000 n 
+0000009349 00000 n 
+0000009606 00000 n 
+0000009703 00000 n 
+trailer
+<<
+/Size 12
+/Info 1 0 R
+/Root 2 0 R
+>>
+startxref
+9805
+%%EOF
diff --git a/lib/galaxy/datatypes/text.py b/lib/galaxy/datatypes/text.py
index 33bdec72306..761e6a6ea78 100644
--- a/lib/galaxy/datatypes/text.py
+++ b/lib/galaxy/datatypes/text.py
@@ -50,13 +50,10 @@ class Html(Text):
         True
         """
         headers = iter_headers(filename, None)
-        try:
-            for i, hdr in enumerate(headers):
-                if hdr and hdr[0].lower().find('<html>') >= 0:
-                    return True
-            return False
-        except Exception:
-            return True
+        for i, hdr in enumerate(headers):
+            if hdr and hdr[0].lower().find('<html>') >= 0:
+                return True
+        return False
 
 
 class Json(Text):
@@ -65,7 +62,7 @@ class Json(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "JavaScript Object Notation (JSON)"
         else:
             dataset.peek = 'file does not exist'
@@ -113,7 +110,7 @@ class Ipynb(Json):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "Jupyter Notebook"
         else:
             dataset.peek = 'file does not exist'
@@ -186,7 +183,7 @@ class Biom1(Json):
     MetadataElement(name="table_columns", default=[], desc="table_columns", param=MetadataParameter, readonly=True, visible=False, optional=True, no_value=[])
 
     def set_peek(self, dataset, is_multi_byte=False):
-        super(Biom1, self).set_peek(dataset, is_multi_byte)
+        super(Biom1, self).set_peek(dataset)
         if not dataset.dataset.purged:
             dataset.blurb = "Biological Observation Matrix v1"
 
@@ -270,7 +267,7 @@ class Obo(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "Open Biomedical Ontology (OBO)"
         else:
             dataset.peek = 'file does not exist'
@@ -309,7 +306,7 @@ class Arff(Text):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = get_file_peek(dataset.file_name)
             dataset.blurb = "Attribute-Relation File Format (ARFF)"
             dataset.blurb += ", %s comments, %s attributes" % (dataset.metadata.comment_lines, dataset.metadata.columns)
         else:
@@ -503,20 +500,19 @@ class SnpSiftDbNSFP(Text):
         This is called only at upload to write the html file
         cannot rename the datasets here - they come with the default unfortunately
         """
-        self.regenerate_primary_file(dataset)
+        return '<html><head><title>SnpSiftDbNSFP Composite Dataset</title></head></html>'
 
     def regenerate_primary_file(self, dataset):
         """
         cannot do this until we are setting metadata
         """
         annotations = "dbNSFP Annotations: %s\n" % ','.join(dataset.metadata.annotation)
-        f = open(dataset.file_name, 'a')
-        if dataset.metadata.bgzip:
-            bn = dataset.metadata.bgzip
-            f.write(bn)
-            f.write('\n')
-        f.write(annotations)
-        f.close()
+        with open(dataset.file_name, 'a') as f:
+            if dataset.metadata.bgzip:
+                bn = dataset.metadata.bgzip
+                f.write(bn)
+                f.write('\n')
+            f.write(annotations)
 
     def set_meta(self, dataset, overwrite=True, **kwd):
         try:
diff --git a/lib/galaxy/datatypes/triples.py b/lib/galaxy/datatypes/triples.py
index 377a47efd3d..c8ce7631d60 100644
--- a/lib/galaxy/datatypes/triples.py
+++ b/lib/galaxy/datatypes/triples.py
@@ -31,7 +31,7 @@ class Triples(data.Data):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'Triple data'
         else:
             dataset.peek = 'file does not exist'
@@ -55,7 +55,7 @@ class NTriples(data.Text, Triples):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'N-Triples triple data'
         else:
             dataset.peek = 'file does not exist'
@@ -78,7 +78,7 @@ class N3(data.Text, Triples):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'Notation-3 Triple data'
         else:
             dataset.peek = 'file does not exist'
@@ -105,7 +105,7 @@ class Turtle(data.Text, Triples):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'Turtle triple data'
         else:
             dataset.peek = 'file does not exist'
@@ -132,7 +132,7 @@ class Rdf(xml.GenericXml, Triples):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'RDF/XML triple data'
         else:
             dataset.peek = 'file does not exist'
@@ -158,7 +158,7 @@ class Jsonld(text.Json, Triples):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'JSON-LD triple data'
         else:
             dataset.peek = 'file does not exist'
@@ -181,7 +181,7 @@ class HDT(binary.Binary, Triples):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'HDT triple data'
         else:
             dataset.peek = 'file does not exist'
diff --git a/lib/galaxy/datatypes/xml.py b/lib/galaxy/datatypes/xml.py
index aba2272c2a7..18ab8009b8f 100644
--- a/lib/galaxy/datatypes/xml.py
+++ b/lib/galaxy/datatypes/xml.py
@@ -21,7 +21,7 @@ class GenericXml(data.Text):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'XML data'
         else:
             dataset.peek = 'file does not exist'
@@ -68,7 +68,7 @@ class MEMEXml(GenericXml):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'MEME XML data'
         else:
             dataset.peek = 'file does not exist'
@@ -85,7 +85,7 @@ class CisML(GenericXml):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'CisML data'
         else:
             dataset.peek = 'file does not exist'
@@ -104,7 +104,7 @@ class Phyloxml(GenericXml):
     def set_peek(self, dataset, is_multi_byte=False):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = 'Phyloxml data'
         else:
             dataset.peek = 'file does not exist'
@@ -139,7 +139,7 @@ class Owl(GenericXml):
 
     def set_peek(self, dataset, is_multi_byte=False):
         if not dataset.dataset.purged:
-            dataset.peek = data.get_file_peek(dataset.file_name, is_multi_byte=is_multi_byte)
+            dataset.peek = data.get_file_peek(dataset.file_name)
             dataset.blurb = "Web Ontology Language OWL"
         else:
             dataset.peek = 'file does not exist'
diff --git a/lib/galaxy/jobs/__init__.py b/lib/galaxy/jobs/__init__.py
index 58f393eab03..8c82a17da06 100644
--- a/lib/galaxy/jobs/__init__.py
+++ b/lib/galaxy/jobs/__init__.py
@@ -1287,15 +1287,9 @@ class JobWrapper(object, HasResourceParameters):
                         dataset.metadata.from_JSON_dict(output_filename, path_rewriter=path_rewriter)
                     try:
                         assert context.get('line_count', None) is not None
-                        if (not dataset.datatype.composite_type and dataset.dataset.is_multi_byte()) or self.tool.is_multi_byte:
-                            dataset.set_peek(line_count=context['line_count'], is_multi_byte=True)
-                        else:
-                            dataset.set_peek(line_count=context['line_count'])
+                        dataset.set_peek(line_count=context['line_count'])
                     except Exception:
-                        if (not dataset.datatype.composite_type and dataset.dataset.is_multi_byte()) or self.tool.is_multi_byte:
-                            dataset.set_peek(is_multi_byte=True)
-                        else:
-                            dataset.set_peek()
+                        dataset.set_peek()
                 else:
                     # Handle an empty dataset.
                     dataset.blurb = "empty"
diff --git a/lib/galaxy/model/__init__.py b/lib/galaxy/model/__init__.py
index 147090a6171..01689a1a555 100644
--- a/lib/galaxy/model/__init__.py
+++ b/lib/galaxy/model/__init__.py
@@ -2071,8 +2071,8 @@ class DatasetInstance(object):
         """Data consists of multi-byte characters"""
         return self.dataset.is_multi_byte()
 
-    def set_peek(self, is_multi_byte=False):
-        return self.datatype.set_peek(self, is_multi_byte=is_multi_byte)
+    def set_peek(self):
+        return self.datatype.set_peek(self)
 
     def init_meta(self, copy_from=None):
         return self.datatype.init_meta(self, copy_from=copy_from)
diff --git a/lib/galaxy/model/migrate/versions/0005_cleanup_datasets_fix.py b/lib/galaxy/model/migrate/versions/0005_cleanup_datasets_fix.py
index 4a86c22d983..c40ec37e151 100644
--- a/lib/galaxy/model/migrate/versions/0005_cleanup_datasets_fix.py
+++ b/lib/galaxy/model/migrate/versions/0005_cleanup_datasets_fix.py
@@ -241,8 +241,8 @@ class DatasetInstance(object):
         """Saves the data on the disc"""
         self.datatype.set_raw_data(self, data)
 
-    def set_peek(self, is_multi_byte=False):
-        return self.datatype.set_peek(self, is_multi_byte=is_multi_byte)
+    def set_peek(self):
+        return self.datatype.set_peek(self)
 
     def init_meta(self, copy_from=None):
         return self.datatype.init_meta(self, copy_from=copy_from)
diff --git a/lib/galaxy/tools/verify/__init__.py b/lib/galaxy/tools/verify/__init__.py
index c2f873dfa45..82fbfce9eb4 100644
--- a/lib/galaxy/tools/verify/__init__.py
+++ b/lib/galaxy/tools/verify/__init__.py
@@ -168,77 +168,74 @@ def files_diff(file1, file2, attributes=None):
             if (line.startswith('+') and not line.startswith('+++')) or (line.startswith('-') and not line.startswith('---')):
                 count += 1
         return count
+
     if not filecmp.cmp(file1, file2):
-        files_differ = False
         if attributes is None:
             attributes = {}
         decompress = attributes.get("decompress", None)
-        if not decompress:
-            local_file = open(file1, 'U').readlines()
-            history_data = open(file2, 'U').readlines()
+        if decompress:
+            # None means all compressed formats are allowed
+            compressed_formats = None
         else:
-            local_file = get_fileobj(file1, 'U').readlines()
-            history_data = get_fileobj(file2, 'U').readlines()
+            compressed_formats = []
+        is_pdf = False
+        try:
+            local_file = get_fileobj(file1, 'U', compressed_formats=compressed_formats).readlines()
+            history_data = get_fileobj(file2, 'U', compressed_formats=compressed_formats).readlines()
+        except UnicodeDecodeError:
+            if file1.endswith('.pdf') or file2.endswith('.pdf'):
+                is_pdf = True
+                local_file = open(file1, 'rb').readlines()
+                history_data = open(file2, 'rb').readlines()
+            else:
+                raise AssertionError("Binary data detected, not displaying diff")
         if attributes.get('sort', False):
             history_data.sort()
-        # Why even bother with the check loop below, why not just use the diff output? This seems wasteful.
-        if len(local_file) == len(history_data):
-            for i in range(len(history_data)):
-                if local_file[i].rstrip('\r\n') != history_data[i].rstrip('\r\n'):
-                    files_differ = True
-                    break
-        else:
-            files_differ = True
-        if files_differ:
-            allowed_diff_count = int(attributes.get('lines_diff', 0))
-            diff = list(difflib.unified_diff(local_file, history_data, "local_file", "history_data"))
-            diff_lines = get_lines_diff(diff)
-            if diff_lines > allowed_diff_count:
-                if 'GALAXY_TEST_RAW_DIFF' in os.environ:
-                    diff_slice = diff
+        allowed_diff_count = int(attributes.get('lines_diff', 0))
+        diff = list(difflib.unified_diff(local_file, history_data, "local_file", "history_data"))
+        diff_lines = get_lines_diff(diff)
+        if diff_lines > allowed_diff_count:
+            if 'GALAXY_TEST_RAW_DIFF' in os.environ:
+                diff_slice = diff
+            else:
+                if len(diff) < 60:
+                    diff_slice = diff[0:40]
                 else:
-                    if len(diff) < 60:
-                        diff_slice = diff[0:40]
-                    else:
-                        diff_slice = diff[:25] + ["********\n", "*SNIP *\n", "********\n"] + diff[-25:]
-                # FIXME: This pdf stuff is rather special cased and has not been updated to consider lines_diff
-                # due to unknown desired behavior when used in conjunction with a non-zero lines_diff
-                # PDF forgiveness can probably be handled better by not special casing by __extension__ here
-                # and instead using lines_diff or a regular expression matching
-                # or by creating and using a specialized pdf comparison function
-                if file1.endswith('.pdf') or file2.endswith('.pdf'):
-                    # PDF files contain creation dates, modification dates, ids and descriptions that change with each
-                    # new file, so we need to handle these differences.  As long as the rest of the PDF file does
-                    # not differ we're ok.
-                    valid_diff_strs = ['description', 'createdate', 'creationdate', 'moddate', 'id', 'producer', 'creator']
-                    valid_diff = False
-                    invalid_diff_lines = 0
-                    for line in diff_slice:
-                        # Make sure to lower case strings before checking.
-                        line = line.lower()
-                        # Diff lines will always start with a + or - character, but handle special cases: '--- local_file \n', '+++ history_data \n'
-                        if (line.startswith('+') or line.startswith('-')) and line.find('local_file') < 0 and line.find('history_data') < 0:
-                            for vdf in valid_diff_strs:
-                                if line.find(vdf) < 0:
-                                    valid_diff = False
-                                else:
-                                    valid_diff = True
-                                    # Stop checking as soon as we know we have a valid difference
-                                    break
-                            if not valid_diff:
-                                invalid_diff_lines += 1
-                    log.info('## files diff on %s and %s lines_diff=%d, found diff = %d, found pdf invalid diff = %d' % (file1, file2, allowed_diff_count, diff_lines, invalid_diff_lines))
-                    if invalid_diff_lines > allowed_diff_count:
-                        # Print out diff_slice so we can see what failed
-                        log.info("###### diff_slice ######")
-                        raise AssertionError("".join(diff_slice))
-                else:
-                    log.info('## files diff on %s and %s lines_diff=%d, found diff = %d' % (file1, file2, allowed_diff_count, diff_lines))
-                    for line in diff_slice:
-                        for char in line:
-                            if ord(char) > 128:
-                                raise AssertionError("Binary data detected, not displaying diff")
+                    diff_slice = diff[:25] + ["********\n", "*SNIP *\n", "********\n"] + diff[-25:]
+            # FIXME: This pdf stuff is rather special cased and has not been updated to consider lines_diff
+            # due to unknown desired behavior when used in conjunction with a non-zero lines_diff
+            # PDF forgiveness can probably be handled better by not special casing by __extension__ here
+            # and instead using lines_diff or a regular expression matching
+            # or by creating and using a specialized pdf comparison function
+            if is_pdf:
+                # PDF files contain creation dates, modification dates, ids and descriptions that change with each
+                # new file, so we need to handle these differences.  As long as the rest of the PDF file does
+                # not differ we're ok.
+                valid_diff_strs = ['description', 'createdate', 'creationdate', 'moddate', 'id', 'producer', 'creator']
+                valid_diff = False
+                invalid_diff_lines = 0
+                for line in diff_slice:
+                    # Make sure to lower case strings before checking.
+                    line = line.lower()
+                    # Diff lines will always start with a + or - character, but handle special cases: '--- local_file \n', '+++ history_data \n'
+                    if (line.startswith('+') or line.startswith('-')) and line.find('local_file') < 0 and line.find('history_data') < 0:
+                        for vdf in valid_diff_strs:
+                            if line.find(vdf) < 0:
+                                valid_diff = False
+                            else:
+                                valid_diff = True
+                                # Stop checking as soon as we know we have a valid difference
+                                break
+                        if not valid_diff:
+                            invalid_diff_lines += 1
+                log.info('## files diff on %s and %s lines_diff=%d, found diff = %d, found pdf invalid diff = %d' % (file1, file2, allowed_diff_count, diff_lines, invalid_diff_lines))
+                if invalid_diff_lines > allowed_diff_count:
+                    # Print out diff_slice so we can see what failed
+                    log.info("###### diff_slice ######")
                     raise AssertionError("".join(diff_slice))
+            else:
+                log.info('## files diff on %s and %s lines_diff=%d, found diff = %d' % (file1, file2, allowed_diff_count, diff_lines))
+                raise AssertionError("".join(diff_slice))
 
 
 def files_re_match(file1, file2, attributes=None):
diff --git a/lib/galaxy/util/compression_utils.py b/lib/galaxy/util/compression_utils.py
index 8d46e80f8b4..7f9ebd4356f 100644
--- a/lib/galaxy/util/compression_utils.py
+++ b/lib/galaxy/util/compression_utils.py
@@ -1,4 +1,5 @@
 import gzip
+import io
 import sys
 import zipfile
 
@@ -9,32 +10,44 @@ from .checkers import (
 
 if sys.version_info < (3, 3):
     import bz2file as bz2
+    gzip.GzipFile.read1 = gzip.GzipFile.read  # workaround for https://bugs.python.org/issue12591
 else:
     import bz2
 
 
-def get_fileobj(filename, mode="r", gzip_only=False, bz2_only=False, zip_only=False):
+def get_fileobj(filename, mode="r", compressed_formats=None):
     """
-    Returns a fileobj. If the file is compressed, return appropriate file reader.
+    Returns a fileobj. If the file is compressed, return an appropriate file
+    reader. In text mode, always use 'utf-8' encoding.
 
     :param filename: path to file that should be opened
     :param mode: mode to pass to opener
-    :param gzip_only: only open file if file is gzip compressed or not compressed
-    :param bz2_only: only open file if file is bz2 compressed or not compressed
-    :param zip_only: only open file if file is zip compressed or not compressed
+    :param compressed_formats: list of allowed compressed file formats among
+      'bz2', 'gzip' and 'zip'. If left to None, all 3 formats are allowed
     """
+    if compressed_formats is None:
+        compressed_formats = ['bz2', 'gzip', 'zip']
+    # Remove 't' from mode, which may cause an error for compressed files
+    mode = mode.replace('t', '')
     # the various compression readers don't support 'U' mode,
     # so we open in 'r'.
     if mode == 'U':
         cmode = 'r'
     else:
         cmode = mode
-    if not bz2_only and not zip_only and is_gzip(filename):
-        return gzip.GzipFile(filename, cmode)
-    if not gzip_only and not zip_only and is_bz2(filename):
-        return bz2.BZ2File(filename, cmode)
-    if not bz2_only and not gzip_only and zipfile.is_zipfile(filename):
+    if 'gzip' in compressed_formats and is_gzip(filename):
+        fh = gzip.GzipFile(filename, cmode)
+    elif 'bz2' in compressed_formats and is_bz2(filename):
+        fh = bz2.BZ2File(filename, cmode)
+    elif 'zip' in compressed_formats and zipfile.is_zipfile(filename):
         # Return fileobj for the first file in a zip file.
         with zipfile.ZipFile(filename, cmode) as zh:
-            return zh.open(zh.namelist()[0], cmode)
-    return open(filename, mode)
+            fh = zh.open(zh.namelist()[0], cmode)
+    elif 'b' in mode:
+        return open(filename, mode)
+    else:
+        return io.open(filename, mode, encoding='utf-8')
+    if 'b' not in mode:
+        return io.TextIOWrapper(fh, encoding='utf-8')
+    else:
+        return fh
diff --git a/lib/tool_shed/util/tool_util.py b/lib/tool_shed/util/tool_util.py
index b9aef505bdf..da0518b1659 100644
--- a/lib/tool_shed/util/tool_util.py
+++ b/lib/tool_shed/util/tool_util.py
@@ -4,8 +4,8 @@ import shutil
 
 import galaxy.tools
 from galaxy import util
+from galaxy.datatypes.sniff import is_column_based
 from galaxy.util import checkers
-from galaxy.util import unicodify
 from galaxy.util.expressions import ExpressionContext
 from galaxy.web.form_builder import SelectField
 from tool_shed.util import basic_util
@@ -125,20 +125,6 @@ def generate_message_for_invalid_tools(app, invalid_file_tups, repository, metad
     return message
 
 
-def get_headers(fname, sep, count=60, is_multi_byte=False):
-    """Returns a list with the first 'count' lines split by 'sep'."""
-    headers = []
-    for idx, line in enumerate(open(fname)):
-        line = line.rstrip('\n\r')
-        if is_multi_byte:
-            line = unicodify(line, 'utf-8')
-            sep = sep.encode('utf-8')
-        headers.append(line.split(sep))
-        if idx == count:
-            break
-    return headers
-
-
 def get_tool_path_install_dir(partial_install_dir, shed_tool_conf_dict, tool_dict, config_elems):
     for elem in config_elems:
         if elem.tag == 'tool':
@@ -184,26 +170,6 @@ def handle_missing_index_file(app, tool_path, sample_files, repository_tools_tup
     return repository_tools_tups, sample_files_copied
 
 
-def is_column_based(fname, sep='\t', skip=0, is_multi_byte=False):
-    """See if the file is column based with respect to a separator."""
-    headers = get_headers(fname, sep, is_multi_byte=is_multi_byte)
-    count = 0
-    if not headers:
-        return False
-    for hdr in headers[skip:]:
-        if hdr and hdr[0] and not hdr[0].startswith('#'):
-            if len(hdr) > 1:
-                count = len(hdr)
-            break
-    if count < 2:
-        return False
-    for hdr in headers[skip:]:
-        if hdr and hdr[0] and not hdr[0].startswith('#'):
-            if len(hdr) != count:
-                return False
-    return True
-
-
 def is_data_index_sample_file(file_path):
     """
     Attempt to determine if a .sample file is appropriate for copying to ~/tool-data when
diff --git a/test-data/1.fastqsanger b/test-data/1.fastqsanger
index 3a1f7901974..1ec085aa290 100644
--- a/test-data/1.fastqsanger
+++ b/test-data/1.fastqsanger
@@ -5,4 +5,4 @@ AATACTTTCGGCGCCCTAAACCAGCTCACTGGGG
 @1831_573_1050/1
 TTTATGGGTATGGCCGCTCACAGGCCAGCGGCCT
 +
-;@@17?@=>7??@A8?==@4A?A4)&+.'&+'1,
\ No newline at end of file
+;@@17?@=>7??@A8?==@4A?A4)&+.'&+'1,
diff --git a/test-data/1.fastqsolexa b/test-data/1.fastqsolexa
index 01ddd7bed12..23d6e5f80d0 100644
--- a/test-data/1.fastqsolexa
+++ b/test-data/1.fastqsolexa
@@ -5,4 +5,4 @@ GAATTGATCAGGACATAGGACAACTGTAGGCACCAT
 @HANNIBAL_1_FC302VTAAXX:2:1:156:340
 GAGTTCTCGTCGCCTGTAGGCACCATCAATCGTATG
 +HANNIBAL_1_FC302VTAAXX:2:1:156:340
-40 15 40 17 6 36 40 40 40 25 40 9 35 33 40 14 14 18 15 17 19 28 31 4 24 18 27 14 15 18 2 8 12 8 11 9
\ No newline at end of file
+40 15 40 17 6 36 40 40 40 25 40 9 35 33 40 14 14 18 15 17 19 28 31 4 24 18 27 14 15 18 2 8 12 8 11 9
diff --git a/test-data/simple_line_alternative.txt b/test-data/simple_line_alternative.txt
index 6966fea9758..56aa6e445c4 100644
--- a/test-data/simple_line_alternative.txt
+++ b/test-data/simple_line_alternative.txt
@@ -1 +1 @@
-This is a different line of text.
\ No newline at end of file
+This is a different line of text.
diff --git a/test-data/simple_lines_interleaved.txt b/test-data/simple_lines_interleaved.txt
index a1ec72a3503..9fb64962198 100644
--- a/test-data/simple_lines_interleaved.txt
+++ b/test-data/simple_lines_interleaved.txt
@@ -1,4 +1,4 @@
 This is a line of text.
 This is a different line of text.
 This is a line of text.
-This is a different line of text.
\ No newline at end of file
+This is a different line of text.
diff --git a/tools/data_source/data_source.py b/tools/data_source/data_source.py
index 93a2c62bee5..01768c69a94 100644
--- a/tools/data_source/data_source.py
+++ b/tools/data_source/data_source.py
@@ -105,7 +105,7 @@ def __main__():
         # here import checks that upload tool performs
         if enhanced_handling:
             try:
-                ext = sniff.handle_uploaded_dataset_file(filename, datatypes_registry, ext=data_dict['ext'], is_multi_byte=is_multi_byte)
+                ext = sniff.handle_uploaded_dataset_file(filename, datatypes_registry, ext=data_dict['ext'])
             except Exception as e:
                 stop_err(str(e))
             info = dict(type='dataset',
diff --git a/tools/data_source/upload.py b/tools/data_source/upload.py
index 03d57ae7d15..1bc55f0469b 100644
--- a/tools/data_source/upload.py
+++ b/tools/data_source/upload.py
@@ -124,7 +124,7 @@ def add_file(dataset, registry, json_file, output_path):
     # Is dataset content multi-byte?
     elif dataset.is_multi_byte:
         data_type = 'multi-byte char'
-        ext = sniff.guess_ext(dataset.path, registry.sniff_order, is_multi_byte=True)
+        ext = sniff.guess_ext(dataset.path, registry.sniff_order)
     # Is dataset content supported sniffable binary?
     else:
         # FIXME: This ignores the declared sniff order in datatype_conf.xml