diff --git a/.changeset/session-expandable-defaults.md b/.changeset/session-expandable-defaults.md
new file mode 100644
index 00000000000..905b3adb933
--- /dev/null
+++ b/.changeset/session-expandable-defaults.md
@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Start expandable session sections collapsed by default.
diff --git a/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanel.kt b/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanel.kt
index 615f52df59e..c1ff05c96d5 100644
--- a/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanel.kt
+++ b/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanel.kt
@@ -391,7 +391,7 @@ class SessionHeaderPanel(
         expand.accessibleContext.accessibleName = KiloBundle.message(key)
     }
 
-    private fun expanded() = PropertiesComponent.getInstance().getBoolean(EXPANDED_KEY, true)
+    private fun expanded() = PropertiesComponent.getInstance().getBoolean(EXPANDED_KEY, false)
 
     private fun sizeTimeline() {
         val size = timeline.preferredSize
diff --git a/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/views/ReasoningView.kt b/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/views/ReasoningView.kt
index bec8c6b6fad..709264e5ad5 100644
--- a/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/views/ReasoningView.kt
+++ b/packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/views/ReasoningView.kt
@@ -109,7 +109,6 @@ class ReasoningView(reasoning: Reasoning) : PartView() {
         body.add(md.component, BorderLayout.CENTER)
 
         add(header, BorderLayout.NORTH)
-        if (canExpand()) add(scroll, BorderLayout.CENTER)
         sync()
     }
 
@@ -122,7 +121,6 @@ class ReasoningView(reasoning: Reasoning) : PartView() {
             md.set(source)
             changed = true
         }
-        changed = syncBody() || changed
         changed = sync() || changed
         if (changed) refresh()
     }
@@ -131,8 +129,7 @@ class ReasoningView(reasoning: Reasoning) : PartView() {
         if (delta.isEmpty()) return
         source += delta
         md.append(delta)
-        var changed = syncBody()
-        changed = sync() || changed
+        val changed = sync()
         if (changed || bodyVisible()) refresh()
     }
 
@@ -209,12 +206,6 @@ class ReasoningView(reasoning: Reasoning) : PartView() {
         return changed
     }
 
-    private fun syncBody(): Boolean {
-        if (!canExpand()) return collapse()
-        if (bodyVisible()) return false
-        return expand()
-    }
-
     private fun setVisible(component: JBLabel, visible: Boolean): Boolean {
         if (component.isVisible == visible) return false
         component.isVisible = visible
diff --git a/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanelTest.kt b/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanelTest.kt
index 217c8ca94d2..361d1846e1c 100644
--- a/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanelTest.kt
+++ b/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/ui/header/SessionHeaderPanelTest.kt
@@ -54,7 +54,7 @@ class SessionHeaderPanelTest : SessionControllerTestBase() {
         val style = SessionEditorStyle.current()
 
         assertTrue(panel.isVisible)
-        assertTrue(panel.isExpanded())
+        assertFalse(panel.isExpanded())
         assertEquals("Generated title", panel.titleText())
         assertEquals("$0.07", panel.costText())
         assertEquals("1%", panel.contextText())
@@ -135,6 +135,9 @@ class SessionHeaderPanelTest : SessionControllerTestBase() {
         val timeline = panel.timelinePanel()
         val bar = panel.contextBar()
 
+        assertFalse(panel.isExpanded())
+        panel.expandButton().doClick()
+
         assertTrue(panel.isExpanded())
         assertSame(body, panel.bodyPanel())
         assertSame(timeline, panel.timelinePanel())
@@ -244,26 +247,27 @@ class SessionHeaderPanelTest : SessionControllerTestBase() {
         val c = promptedHeader()
         val panel = SessionHeaderPanel(c, parent)
 
-        assertTrue(panel.isExpanded())
-        assertEquals("Hide session metrics", panel.expandTip())
-
-        panel.expandButton().doClick()
-        emit(ChatEventDto.SessionUpdated("ses_test", session("ses_test", title = "New title")))
-
         assertFalse(panel.isExpanded())
         assertEquals("Show session metrics", panel.expandTip())
 
         panel.expandButton().doClick()
-        emit(ChatEventDto.MessageUpdated("ses_test", assistant(cost = 0.2)))
+        emit(ChatEventDto.SessionUpdated("ses_test", session("ses_test", title = "New title")))
 
         assertTrue(panel.isExpanded())
         assertEquals("Hide session metrics", panel.expandTip())
+
+        panel.expandButton().doClick()
+        emit(ChatEventDto.MessageUpdated("ses_test", assistant(cost = 0.2)))
+
+        assertFalse(panel.isExpanded())
+        assertEquals("Show session metrics", panel.expandTip())
     }
 
     fun `test collapse persists and new header starts collapsed`() {
         val c = promptedHeader()
         val panel = SessionHeaderPanel(c, parent)
 
+        panel.expandButton().doClick()
         panel.expandButton().doClick()
 
         assertFalse(panel.isExpanded())
@@ -294,6 +298,7 @@ class SessionHeaderPanelTest : SessionControllerTestBase() {
     }
 
     fun `test hidden empty header collapse keeps saved expansion preference`() {
+        PropertiesComponent.getInstance().setValue(SessionHeaderPanel.EXPANDED_KEY, "true")
         appRpc.state.value = ai.kilocode.rpc.dto.KiloAppStateDto(ai.kilocode.rpc.dto.KiloAppStatusDto.READY)
         projectRpc.state.value = workspaceReady()
         val c = controller()
diff --git a/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/views/ReasoningViewTest.kt b/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/views/ReasoningViewTest.kt
index 6cae7834def..f0cf4d20169 100644
--- a/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/views/ReasoningViewTest.kt
+++ b/packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/session/views/ReasoningViewTest.kt
@@ -8,61 +8,58 @@ import javax.swing.ScrollPaneConstants
 @Suppress("UnstableApiUsage")
 class ReasoningViewTest : BasePlatformTestCase() {
 
-    fun `test completed reasoning is expanded by default`() {
+    fun `test completed reasoning is collapsed by default`() {
         val view = ReasoningView(reasoning("p1", done = true, text = "one\ntwo\nthree\nfour"))
 
-        assertTrue(view.isExpanded())
+        assertFalse(view.isExpanded())
         assertEquals("Reasoning", view.headerText())
         assertEquals("one\ntwo\nthree\nfour", view.markdown())
         assertTrue(view.hasToggle())
-        assertTrue(view.bodyVisible())
+        assertFalse(view.bodyVisible())
         assertTrue(view.bodyCreated())
     }
 
     fun `test short completed reasoning is collapsible`() {
         val view = ReasoningView(reasoning("p1", done = true, text = "one\ntwo\nthree"))
 
-        assertTrue(view.isExpanded())
+        assertFalse(view.isExpanded())
         assertTrue(view.hasToggle())
         view.toggle()
-        assertFalse(view.isExpanded())
-        assertFalse(view.bodyVisible())
+        assertTrue(view.isExpanded())
+        assertTrue(view.bodyVisible())
         assertTrue(view.bodyCreated())
     }
 
-    fun `test streaming reasoning is expanded by default`() {
+    fun `test streaming reasoning is collapsed by default`() {
         val view = ReasoningView(reasoning("p1", done = false, text = "one\ntwo\nthree\nfour"))
 
-        assertTrue(view.isExpanded())
+        assertFalse(view.isExpanded())
         assertTrue(view.hasToggle())
     }
 
-    fun `test update to done preserves visible reasoning`() {
+    fun `test update to done preserves collapsed reasoning`() {
         val view = ReasoningView(reasoning("p1", done = false, text = "one\ntwo\nthree\nfour"))
 
         view.update(reasoning("p1", done = true, text = "one\ntwo\nthree\nfour"))
 
-        assertTrue(view.isExpanded())
+        assertFalse(view.isExpanded())
         assertEquals("one\ntwo\nthree\nfour", view.markdown())
     }
 
     fun `test toggle opens and closes reasoning`() {
         val view = ReasoningView(reasoning("p1", done = true, text = "one\ntwo\nthree\nfour"))
 
+        view.toggle()
         assertTrue(view.isExpanded())
         view.toggle()
         assertFalse(view.isExpanded())
-        view.toggle()
-        assertTrue(view.isExpanded())
     }
 
-    fun `test collapsed reasoning expands on update`() {
+    fun `test collapsed reasoning stays collapsed on update`() {
         val view = ReasoningView(reasoning("p1", done = false, text = "one\ntwo"))
-
-        view.toggle()
         view.update(reasoning("p1", done = true, text = "one\ntwo\nthree"))
 
-        assertTrue(view.isExpanded())
+        assertFalse(view.isExpanded())
         assertEquals("one\ntwo\nthree", view.markdown())
     }
 
@@ -72,39 +69,38 @@ class ReasoningViewTest : BasePlatformTestCase() {
         view.appendDelta("b")
 
         assertEquals("ab", view.markdown())
-        assertTrue(view.isExpanded())
+        assertFalse(view.isExpanded())
     }
 
-    fun `test blank reasoning expands when delta arrives`() {
+    fun `test blank reasoning stays collapsed when delta arrives`() {
         val view = ReasoningView(reasoning("p1", done = false, text = ""))
 
         view.appendDelta("b")
 
         assertEquals("b", view.markdown())
         assertTrue(view.bodyCreated())
-        assertTrue(view.bodyVisible())
+        assertFalse(view.bodyVisible())
+        assertTrue(view.hasToggle())
     }
 
-    fun `test collapsed append reattaches eager reasoning body`() {
+    fun `test collapsed append keeps eager reasoning body detached`() {
         val view = ReasoningView(reasoning("p1", done = false, text = "a"))
-        view.toggle()
 
         view.appendDelta("b")
 
         assertEquals("ab", view.markdown())
         assertTrue(view.bodyCreated())
-        assertTrue(view.bodyVisible())
+        assertFalse(view.bodyVisible())
     }
 
-    fun `test collapsed update reattaches eager reasoning body`() {
+    fun `test collapsed update keeps eager reasoning body detached`() {
         val view = ReasoningView(reasoning("p1", done = false, text = "a"))
-        view.toggle()
 
         view.update(reasoning("p1", done = false, text = "abc"))
 
         assertEquals("abc", view.markdown())
         assertTrue(view.bodyCreated())
-        assertTrue(view.bodyVisible())
+        assertFalse(view.bodyVisible())
     }
 
     fun `test reasoning reuses eager markdown body`() {
@@ -116,7 +112,7 @@ class ReasoningViewTest : BasePlatformTestCase() {
         view.toggle()
 
         assertSame(component, view.md.component)
-        assertFalse(view.bodyVisible())
+        assertTrue(view.bodyVisible())
     }
 
     fun `test blank reasoning has no toggle`() {
@@ -158,6 +154,7 @@ class ReasoningViewTest : BasePlatformTestCase() {
 
     fun `test expanded reasoning body is capped to five rows`() {
         val view = ReasoningView(reasoning("p1", done = false, text = (1..20).joinToString("\n") { "line $it" }))
+        view.toggle()
 
         assertEquals(5, view.bodyMaxRows())
         assertTrue(view.preferredSize.height > 0)