diff --git a/Sources/TextBoxInput.swift b/Sources/TextBoxInput.swift
index d2d6309817c..9f1a5fc41ad 100644
--- a/Sources/TextBoxInput.swift
+++ b/Sources/TextBoxInput.swift
@@ -3420,17 +3420,51 @@ struct TextBoxInputView: NSViewRepresentable {
             let nextText = textView.plainText()
             let nextAttachments = textView.inlineAttachments()
             let nextHasPendingAttachmentUpload = textView.hasPendingAttachmentUploadPlaceholder()
-            let contentChanged = parent.text != nextText
-                || parent.attachments.map(\.id) != nextAttachments.map(\.id)
-                || parent.hasPendingAttachmentUpload != nextHasPendingAttachmentUpload
-            parent.text = nextText
-            parent.attachments = nextAttachments
-            parent.hasPendingAttachmentUpload = nextHasPendingAttachmentUpload
+            let didChangeText = parent.text != nextText
+            let didChangeAttachments = Self.attachmentsDiffer(parent.attachments, nextAttachments)
+            let didChangePendingUpload = parent.hasPendingAttachmentUpload != nextHasPendingAttachmentUpload
+            let contentChanged = didChangeText || didChangeAttachments || didChangePendingUpload
+            if didChangeText {
+                parent.text = nextText
+            }
+            if didChangeAttachments {
+                parent.attachments = nextAttachments
+            }
+            if didChangePendingUpload {
+                parent.hasPendingAttachmentUpload = nextHasPendingAttachmentUpload
+            }
             if contentChanged {
                 parent.onContentChanged()
             }
         }
 
+        private static func attachmentsDiffer(
+            _ currentAttachments: [TextBoxAttachment],
+            _ nextAttachments: [TextBoxAttachment]
+        ) -> Bool {
+            guard currentAttachments.count == nextAttachments.count else { return true }
+            return zip(currentAttachments, nextAttachments).contains { current, next in
+                current.id != next.id
+                    || current.displayName != next.displayName
+                    || current.submissionText != next.submissionText
+                    || current.submissionPath != next.submissionPath
+                    || current.localURL != next.localURL
+                    || current.cleanupLocalURLWhenDisposed != next.cleanupLocalURLWhenDisposed
+                    || !sameThumbnail(current.thumbnail, next.thumbnail)
+            }
+        }
+
+        private static func sameThumbnail(_ currentThumbnail: NSImage?, _ nextThumbnail: NSImage?) -> Bool {
+            switch (currentThumbnail, nextThumbnail) {
+            case (nil, nil):
+                true
+            case let (current?, next?):
+                current === next
+            default:
+                false
+            }
+        }
+
         func recalculateHeight(_ textView: NSTextView) {
             guard let layoutManager = textView.layoutManager,
                   let textContainer = textView.textContainer else { return }
diff --git a/cmux.xcodeproj/project.pbxproj b/cmux.xcodeproj/project.pbxproj
index 82cabb06bbc..983163c8328 100644
--- a/cmux.xcodeproj/project.pbxproj
+++ b/cmux.xcodeproj/project.pbxproj
@@ -530,6 +530,7 @@
 		C13519000000000000000001 /* TerminalStartupEnvironment.swift in Sources */ = {isa = PBXBuildFile; fileRef = C13519000000000000000002 /* TerminalStartupEnvironment.swift */; };
 		A5001532 /* TerminalWindowPortal.swift in Sources */ = {isa = PBXBuildFile; fileRef = A5001531 /* TerminalWindowPortal.swift */; };
 		D0B10006A1B2C3D4E5F60001 /* TerminalWindowPortalDebug.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0B10007A1B2C3D4E5F60001 /* TerminalWindowPortalDebug.swift */; };
+		C5345001A1B2C3D4E5F60719 /* TextBoxContentSyncTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C5345002A1B2C3D4E5F60719 /* TextBoxContentSyncTests.swift */; };
 		C0DE7B100000000000000001 /* TextBoxInput.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0DE7B100000000000000002 /* TextBoxInput.swift */; };
 		C0DE7B310000000000000001 /* TextBoxMentionCachedIndex.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0DE7B310000000000000002 /* TextBoxMentionCachedIndex.swift */; };
 		C0DE7B250000000000000001 /* TextBoxMentionCandidate.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0DE7B250000000000000002 /* TextBoxMentionCandidate.swift */; };
@@ -1169,6 +1170,7 @@
 		C13519000000000000000002 /* TerminalStartupEnvironment.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalStartupEnvironment.swift; sourceTree = "<group>"; };
 		A5001531 /* TerminalWindowPortal.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalWindowPortal.swift; sourceTree = "<group>"; };
 		D0B10007A1B2C3D4E5F60001 /* TerminalWindowPortalDebug.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalWindowPortalDebug.swift; sourceTree = "<group>"; };
+		C5345002A1B2C3D4E5F60719 /* TextBoxContentSyncTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextBoxContentSyncTests.swift; sourceTree = "<group>"; };
 		C0DE7B100000000000000002 /* TextBoxInput.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextBoxInput.swift; sourceTree = "<group>"; };
 		C0DE7B310000000000000002 /* TextBoxMentionCachedIndex.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextBoxMentionCachedIndex.swift; sourceTree = "<group>"; };
 		C0DE7B250000000000000002 /* TextBoxMentionCandidate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextBoxMentionCandidate.swift; sourceTree = "<group>"; };
@@ -1849,6 +1851,7 @@
 				F5310001A1B2C3D4E5F60718 /* RovoDevHookConfigTests.swift */,
 				FA100001A1B2C3D4E5F60718 /* BrowserImportMappingTests.swift */,
 				F6000001A1B2C3D4E5F60718 /* AppDelegateShortcutRoutingTests.swift */,
+				C5345002A1B2C3D4E5F60719 /* TextBoxContentSyncTests.swift */,
 				C0DE7B300000000000000002 /* TextBoxMentionCompletionTests.swift */,
 					C1713005C1713005C1713005 /* CommandPaletteShortcutCustomizationTests.swift */,
 					17FCD4CC61D54A2F8F2F463D /* AppDelegateBareSpaceShortcutRoutingTests.swift */,
@@ -2881,6 +2884,7 @@
 				A5A5A503A1B2C3D4E5F60718 /* TerminalNotificationQueueTests.swift in Sources */,
 					A5E380700000000000000001 /* TerminalNotificationSocketActionTests.swift in Sources */,
 				C0DE53360000000000000001 /* TerminalSearchOverlayMouseReleaseTests.swift in Sources */,
+				C5345001A1B2C3D4E5F60719 /* TextBoxContentSyncTests.swift in Sources */,
 				C0DE7B300000000000000001 /* TextBoxMentionCompletionTests.swift in Sources */,
 				F50030040000000000000001 /* TitlebarInteractiveControlTests.swift in Sources */,
 				D3284001A1B2C3D4E5F60718 /* TraditionalChineseIMENumpadRegressionTests.swift in Sources */,
diff --git a/cmuxTests/TextBoxContentSyncTests.swift b/cmuxTests/TextBoxContentSyncTests.swift
new file mode 100644
index 00000000000..129f67e5079
--- /dev/null
+++ b/cmuxTests/TextBoxContentSyncTests.swift
@@ -0,0 +1,79 @@
+import AppKit
+import SwiftUI
+import Testing
+
+#if canImport(cmux_DEV)
+@testable import cmux_DEV
+#elseif canImport(cmux)
+@testable import cmux
+#endif
+
+@MainActor
+struct TextBoxContentSyncTests {
+    @Test func contentSyncSkipsUnchangedSwiftUIBindings() {
+        var text = "same"
+        var attachments: [TextBoxAttachment] = []
+        var height: CGFloat = 24
+        var hasPendingAttachmentUpload = false
+        var textWriteCount = 0
+        var attachmentWriteCount = 0
+        var pendingWriteCount = 0
+        var contentChangeCount = 0
+
+        let inputView = TextBoxInputView(
+            text: Binding(
+                get: { text },
+                set: { newValue in
+                    textWriteCount += 1
+                    text = newValue
+                }
+            ),
+            attachments: Binding(
+                get: { attachments },
+                set: { newValue in
+                    attachmentWriteCount += 1
+                    attachments = newValue
+                }
+            ),
+            textViewHeight: Binding(get: { height }, set: { height = $0 }),
+            hasPendingAttachmentUpload: Binding(
+                get: { hasPendingAttachmentUpload },
+                set: { newValue in
+                    pendingWriteCount += 1
+                    hasPendingAttachmentUpload = newValue
+                }
+            ),
+            font: NSFont.systemFont(ofSize: 14),
+            backgroundColor: .textBackgroundColor,
+            foregroundColor: .labelColor,
+            terminalTitle: "codex",
+            completionRootDirectory: nil,
+            onSubmit: {},
+            onEscape: {},
+            onFocusTextBox: {},
+            onToggleFocus: {},
+            onForwardText: { _, _ in },
+            onForwardKey: { _ in },
+            onForwardControl: { _ in },
+            onPaste: { _, _ in false },
+            onInsertFileURLs: { _, _ in false },
+            onChooseFiles: {},
+            onContentChanged: { contentChangeCount += 1 },
+            onTextViewCreated: { _ in },
+            onTextViewMovedToWindow: { _ in },
+            onTextViewDismantled: { _ in }
+        )
+        let coordinator = TextBoxInputView.Coordinator(parent: inputView)
+        let textView = TextBoxInputTextView(frame: NSRect(x: 0, y: 0, width: 320, height: 30))
+        textView.font = NSFont.systemFont(ofSize: 14)
+        textView.textColor = .labelColor
+        textView.string = "same"
+
+        coordinator.textDidChange(Notification(name: NSText.didChangeNotification, object: textView))
+
+        #expect(textWriteCount == 0)
+        #expect(attachmentWriteCount == 0)
+        #expect(pendingWriteCount == 0)
+        #expect(contentChangeCount == 0)
+    }
+}