[BUG] Claude Code tab severely laggy in Desktop app while Chat tab is fluid. Windows MSIX, CLI unaffected
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?
The Claude Code tab in the Claude Desktop app has severe UI latency. Every click
takes 1-5 seconds to register, and Windows regularly displays "not responding"
for approximately 2 seconds during interaction. It feels like using a low-spec
machine running Windows 98/XP.
Critically, the Chat tab in the same application is perfectly fluid. Only the
Code tab is affected.
Claude Code CLI in the terminal on the same machine is instantaneous, which
isolates the problem to the Electron renderer rather than to Claude Code itself,
my configuration, my account, or my hardware.
This matches #31643, where the same Desktop-slow / terminal-fast split was
reported on Windows MSIX.
What Should Happen?
The Code tab should be as responsive as the Chat tab. Clicks should register
immediately and the UI should never block the main thread long enough for
Windows to report the window as unresponsive.
Error Messages/Logs
No error dialogs are shown. The failure mode is silent UI blocking.
From /doctor transcript analysis (43 sessions over 34 days, 2026-06-25 to
2026-07-29):
- ~30 `automode-unavailable` events (auto mode was active but its classifier
could not be reached)
- Built-in SessionStart hook: median 4.3s, max 26.7s
- Built-in Stop hook: median ~1s, one spike to 57.6s with 1 timeout
These are app-managed hooks, not user-configured — there are no hooks in my
settings.Steps to Reproduce
- Install Claude Desktop on Windows 11 via the Microsoft Store (MSIX package)
- Open the app and use the Chat tab it is fluid
- Switch to the Code tab
- Click through the UI (menus, settings, screen changes) with no project open
- Every click takes 1-2s; the window intermittently reports "not responding"
Reproduces with a brand-new Enterprise account and zero projects configured.
Claude Model
None
Is this a regression?
Yes, this worked in a previous version
Last Working Version
_No response_
Claude Code Version
2.1.220 (Claude Code)
Platform
Anthropic API
Operating System
Windows
Terminal/Shell
PowerShell
Additional Information
Environment
- OS: Windows 11
- CPU: sustained 4.38 GHz (power plan set to maximum performance)
- RAM: 32 GB, 55% used
- GPU: Intel Iris Xe (integrated) + NVIDIA T600 Laptop — dual GPU laptop
- Disk: NVMe SSD, 1% utilization
- Network: Intel Wi-Fi 6E AX211, connected at 802.11ac
Ruled out
| Test | Result |
|---|---|
| /doctor in an empty folder | Clean — no CLAUDE.md, no hooks, no local MCP servers |
| Fresh Enterprise account, zero projects | Same lag |
| Resource usage during lag | 0% CPU across 13 Claude processes, NVIDIA 0% at 48°C, disk 1% |
| --disable-gpu-compositing launch flag | No effect |
| GPU preference forced to iGPU via Windows Graphics settings | No effect |
| Efficiency mode (EcoQoS) disabled on Claude processes | No effect |
| Power plan set to maximum performance | Slight improvement only |
| Chromium caches cleared (Cache, Code Cache, GPUCache, Dawn*, Crashpad) | No effect |
| Claude Code CLI in terminal, same machine | Instantaneous |
Note that the GPU findings match #56805: neither GPU preference setting resolves
the issue. In my case --disable-gpu-compositing did not help either, which
suggests a different root cause than the DWM compositing conflict.
Cowork is installed (cowork-svc present, claude-code-vm and vm_bundles in
%APPDATA%\Claude) but I do not use it.
Related issues
- #31643 — Desktop laggy, terminal instantaneous, same MSIX packaging
- #56805 — GPU compositing on multi-GPU Windows systems
- #26302 — UI lag regression after Desktop update
- #48299 — Electron renderer performance roadmap