[BUG] Desktop — Progressive Renderer Degradation on Windows 11 / NVIDIA G-Sync

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Bug Report: Claude Desktop — Progressive Renderer Degradation on Windows 11 / NVIDIA G-Sync

Reported by: David Mitchell
Date: June 2026
App Version: Claude Desktop 1.11187.4
Install type: MSIX / Windows Store package (Claude_pzs8sxrjxfjjc)

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Environment

|Property |Value |
|---------------------|----------------------------------------------------------------------------------|
|OS |Windows 11 (recent Windows Update applied) |
|App version |Claude Desktop 1.11187.4 |
|Install method |MSIX via Microsoft Store / WindowsApps |
|Exe path |C:\Program Files\WindowsApps\Claude_1.5354.0.0_x64__pzs8sxrjxfjjc\app\Claude.exe|
|GPU |NVIDIA GeForce GTX 1080 |
|GPU driver |581.57 (Game Ready; updated via Windows Update) |
|Monitor |ASUS ROG — G-Sync enabled, 2560×1440 |
|Connection |DisplayPort |
|Windows display scale|100% |
|G-Sync mode |Enabled for windowed and full screen |

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Bug Description

Claude Desktop’s Electron renderer enters a progressively degraded state during normal use. Affected regions become visually blurry/soft. The blur is a rendering artefact, not a display or cable issue.

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Symptoms

• Sidebar and conversation pane progressively blur during use
• Entry/compose pane remains sharp throughout
• Blur is visible in Windows screenshots (confirms software/rendering issue, not hardware)
• Blur is triggered by window movement — moving the Claude window or any other open window causes the degradation
• Blur is intermittent but reproducible
• Browser version (claude.ai in Chrome/Edge) is completely unaffected

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Temporary Workarounds (confirmed effective)

All of the following force a re-rasterisation and restore sharpness:

|Workaround |Notes |
|----------------------------|-------------------------------------------------|
|Ctrl++ then Ctrl+0 |Zoom in then reset — forces full renderer repaint|
|Maximise then restore window|Forces DWM recomposition |
|Refocus the window |Clicking back into Claude restores sharpness |

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Root Cause Hypothesis

Electron renderer + Windows DWM compositor + NVIDIA G-Sync interaction.

When any window is moved, Windows DWM enters a live compositing state and redraws the desktop. The Claude Electron renderer appears to drop to a lower-quality rendering surface during this process and does not recover automatically.

Specifically suspected:

• Windows 11 “Optimisations for windowed games” presentation model
• G-Sync VRR interaction with windowed Electron surfaces
• Electron GPU compositing not correctly invalidating/repainting regions after DWM compositing events

Supporting evidence from GitHub issue #56805:

“Electron GPU compositing causes excessive redraws. When the mouse moves over the Claude window, the Electron renderer triggers continuous frame repaints. DWM then re-composites these frames on the NVIDIA GPU, creating a bottleneck. Launching Claude Desktop with --disable-gpu-compositing resolves the issue.”

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Solutions Attempted

✅ Previously effective — no longer sufficient after driver/Windows update

|Fix |Method |Outcome |
|------------------------------------------|-----------------------------------------------------------------|-----------------------------------------------------------------------------|
|Monitor Technology → Fixed Refresh |NVIDIA Control Panel → Program Settings → claude_pzs8sxrjxfjjc |Previously fixed blur on focus change; no longer sufficient |
|Disable “Optimisations for windowed games”|Windows Settings → System → Display → Graphics → Claude → Options|Previously fixed window-movement blur; still applied but no longer sufficient|

❌ Attempted — ineffective

|Fix |Method |Outcome |
|----------------------------------------------------------|----------------------------------------------------|---------------------------------------------------------------------------|
|OverlayTestMode = 5 registry key |HKLM\SOFTWARE\Microsoft\Windows\Dwm — disables MPO|No effect |
|App update to latest version |Relaunched via in-app update prompt |No effect |
|Reinstall from claude.ai/download |Uninstall + fresh MSIX install |No effect — MSIX packaging reinstalls to WindowsApps regardless of source|
|DPI compatibility override |Right-click exe → Properties → Compatibility |Blocked — WindowsApps is a protected directory |
|--disable-gpu / --disable-gpu-compositing launch flags|Not applicable |Blocked by MSIX sandboxing |
|Transparency effects disabled |Windows Settings → Accessibility → Visual effects |No effect |

🔲 Not yet attempted

|Fix |Method |
|--------------------------------|-------------------------------------------------------------------|
|Disable FXAA for Claude |NVIDIA Control Panel → Program Settings → Antialiasing - FXAA → Off|
|Disable G-Sync for windowed mode|NVIDIA Control Panel → Set up G-SYNC → Full screen only |
|Switch to NVIDIA Studio Driver |Download from nvidia.com — replaces Game Ready driver |

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Key Constraint: MSIX Packaging Blocks Standard Electron Fixes

Claude Desktop on Windows is distributed exclusively as an MSIX package installed to C:\Program Files\WindowsApps\. This has significant consequences:

• DPI compatibility settings cannot be applied — the exe is in a protected directory
• Electron GPU launch flags are blocked — --disable-gpu, --disable-gpu-compositing, ELECTRON_EXTRA_LAUNCH_ARGS are all ignored
• Per-app GPU control panel profiles have limited effect — the sandboxed presentation path overrides some NVIDIA Control Panel settings
• Users cannot work around this — the fix must come from Anthropic

Reference: GitHub issue #63650 — Claude Desktop blurry on high-DPI display due to MSIX packaging blocking DPI override

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Impact

• Affects all Windows users running Claude Desktop on NVIDIA G-Sync setups
• Cowork and Claude Code require the desktop app — browser workaround is not viable for these users
• The --disable-gpu-compositing flag is confirmed to resolve the issue but is inaccessible due to MSIX packaging

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Suggested Engineering Actions

1. Expose a user-configurable GPU flag mechanism that works within the MSIX sandbox — or pass --disable-gpu-compositing by default on Windows
2. Investigate Electron renderer invalidation on DWM compositing events — the renderer should recover automatically without requiring a zoom or resize
3. Consider offering a non-MSIX installer for Windows — this would restore all standard Electron DPI/GPU workarounds to users and reduce support burden
4. Test against G-Sync + windowed mode configurations — this is a common setup among the professional/prosumer audience Claude targets

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References

• #56805 — Screen Flickering & Mouse Lag on Windows
• #63650 — Claude Desktop blurry due to MSIX packaging
• Google AI Overview: “Claude app window goes blurry when looking at other windows” — identifies NVIDIA G-Sync / Electron GPU context loss as root cause

What Should Happen?

No issues with display…text should not blur.

Error Messages/Logs

No error messages

Steps to Reproduce

Add this section to the report:

Steps to Reproduce

1. Install Claude Desktop on Windows 11 via the official installer from claude.ai/download (installs as MSIX package)
2. Open Claude Desktop
3. Open any other application window alongside Claude
4. Move any window (Claude or another application) around the screen
5. Observe sidebar and conversation pane progressively blur
6. Note that the compose/entry pane remains sharp
7. Confirm blur is visible in a Windows Snipping Tool screenshot (rules out hardware/cable/monitor cause)

To confirm the renderer has degraded:

• Press Ctrl++ then Ctrl+0 — sharpness immediately restores
• Or maximise then restore the Claude window
• Or click away then refocus the Claude window

Expected behaviour: Renderer maintains sharpness throughoutActual behaviour: Renderer enters degraded state after window movement, requires manual forced redraw to recover

That’s precise enough for an engineer to reproduce it on a matching setup.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Desktop version 1.11187.4

Platform

Other

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

References
• #56805 — Screen Flickering & Mouse Lag on Windows
• #63650 — Claude Desktop blurry due to MSIX packaging
• Google AI Overview: “Claude app window goes blurry when looking at other windows” — identifies NVIDIA G-Sync / Electron GPU context loss as root cause