diff --git a/packages/kilo-vscode/tests/unit/image-attachments-utils.test.ts b/packages/kilo-vscode/tests/unit/image-attachments-utils.test.ts
new file mode 100644
index 0000000000..c5b50bbaeb
--- /dev/null
+++ b/packages/kilo-vscode/tests/unit/image-attachments-utils.test.ts
@@ -0,0 +1,58 @@
+import { describe, it, expect } from "bun:test"
+import {
+  ACCEPTED_IMAGE_TYPES,
+  isAcceptedImageType,
+  isDragLeavingComponent,
+} from "../../webview-ui/src/hooks/image-attachments-utils"
+
+describe("ACCEPTED_IMAGE_TYPES", () => {
+  it("includes the standard image MIME types", () => {
+    expect(ACCEPTED_IMAGE_TYPES).toContain("image/png")
+    expect(ACCEPTED_IMAGE_TYPES).toContain("image/jpeg")
+    expect(ACCEPTED_IMAGE_TYPES).toContain("image/gif")
+    expect(ACCEPTED_IMAGE_TYPES).toContain("image/webp")
+  })
+})
+
+describe("isAcceptedImageType", () => {
+  it("returns true for accepted types", () => {
+    expect(isAcceptedImageType("image/png")).toBe(true)
+    expect(isAcceptedImageType("image/jpeg")).toBe(true)
+    expect(isAcceptedImageType("image/gif")).toBe(true)
+    expect(isAcceptedImageType("image/webp")).toBe(true)
+  })
+
+  it("returns false for non-image types", () => {
+    expect(isAcceptedImageType("application/pdf")).toBe(false)
+    expect(isAcceptedImageType("text/plain")).toBe(false)
+    expect(isAcceptedImageType("video/mp4")).toBe(false)
+  })
+
+  it("returns false for empty string", () => {
+    expect(isAcceptedImageType("")).toBe(false)
+  })
+
+  it("returns false for image types not in the accepted list", () => {
+    expect(isAcceptedImageType("image/svg+xml")).toBe(false)
+    expect(isAcceptedImageType("image/bmp")).toBe(false)
+  })
+})
+
+describe("isDragLeavingComponent", () => {
+  it("returns true when relatedTarget is null (left the page)", () => {
+    const el = { contains: () => false } as unknown as HTMLElement
+    expect(isDragLeavingComponent(null, el)).toBe(true)
+  })
+
+  it("returns false when relatedTarget is a child (contains returns true)", () => {
+    const child = {} as EventTarget
+    const parent = { contains: (n: Node) => n === child } as unknown as HTMLElement
+    expect(isDragLeavingComponent(child, parent)).toBe(false)
+  })
+
+  it("returns true when relatedTarget is outside (contains returns false)", () => {
+    const outside = {} as EventTarget
+    const container = { contains: () => false } as unknown as HTMLElement
+    expect(isDragLeavingComponent(outside, container)).toBe(true)
+  })
+})
diff --git a/packages/kilo-vscode/webview-ui/src/hooks/image-attachments-utils.ts b/packages/kilo-vscode/webview-ui/src/hooks/image-attachments-utils.ts
new file mode 100644
index 0000000000..39bd74e01f
--- /dev/null
+++ b/packages/kilo-vscode/webview-ui/src/hooks/image-attachments-utils.ts
@@ -0,0 +1,15 @@
+export const ACCEPTED_IMAGE_TYPES = ["image/png", "image/jpeg", "image/gif", "image/webp"]
+
+/** Returns true if the given MIME type is an accepted image type. */
+export function isAcceptedImageType(mimeType: string): boolean {
+  return ACCEPTED_IMAGE_TYPES.includes(mimeType)
+}
+
+/**
+ * Check if a drag-leave event is leaving the component (not just entering a child).
+ * Returns true if dragging has actually left the component boundary.
+ */
+export function isDragLeavingComponent(relatedTarget: EventTarget | null, currentTarget: HTMLElement): boolean {
+  if (!relatedTarget) return true
+  return !currentTarget.contains(relatedTarget as Node)
+}
diff --git a/packages/kilo-vscode/webview-ui/src/hooks/useImageAttachments.ts b/packages/kilo-vscode/webview-ui/src/hooks/useImageAttachments.ts
index 7853908337..f9f128cd35 100644
--- a/packages/kilo-vscode/webview-ui/src/hooks/useImageAttachments.ts
+++ b/packages/kilo-vscode/webview-ui/src/hooks/useImageAttachments.ts
@@ -1,6 +1,7 @@
 import { createSignal } from "solid-js"
+import { ACCEPTED_IMAGE_TYPES, isAcceptedImageType, isDragLeavingComponent } from "./image-attachments-utils"
 
-export const ACCEPTED_IMAGE_TYPES = ["image/png", "image/jpeg", "image/gif", "image/webp"]
+export { ACCEPTED_IMAGE_TYPES }
 
 export interface ImageAttachment {
   id: string
@@ -14,7 +15,7 @@ export function useImageAttachments() {
   const [dragging, setDragging] = createSignal(false)
 
   const add = (file: File) => {
-    if (!ACCEPTED_IMAGE_TYPES.includes(file.type)) return
+    if (!isAcceptedImageType(file.type)) return
     const reader = new FileReader()
     reader.onload = () => {
       const attachment: ImageAttachment = {
@@ -53,7 +54,7 @@ export function useImageAttachments() {
   }
 
   const handleDragLeave = (event: DragEvent) => {
-    if (!event.relatedTarget || !(event.currentTarget as HTMLElement).contains(event.relatedTarget as Node)) {
+    if (isDragLeavingComponent(event.relatedTarget, event.currentTarget as HTMLElement)) {
       setDragging(false)
     }
   }