[Bug] Claude Code performance degradation - slow execution

Found 3 possible duplicate issues:

1. https://github.com/anthropics/claude-code/issues/11201
2. https://github.com/anthropics/claude-code/issues/10021
3. https://github.com/anthropics/claude-code/issues/3152

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🤖 Generated with Claude Code

Have had a similar issue the past 14 hours on Claude Code on Windows, run both from VS Code and Command line. Tried removing all cached files, restarting, updating Claude.. no fixes yet. Practically unusable as it starts to become unresponsive (for up to 20 minutes at a time) when working on tasks - it kicks in at very early stages too - long before any auto-compact. Larger scripts obviously more problematic.

same problem very slow

2.0.50 is unusable on Windows. It starts fine, but performance degrades in less than a minute after claude starts doing any work. Terminal freezes completely and even the timer stops updating.

same problem on windows using WSL. Runs well for a few seconds but as it now sends full code files for review instead of just the relevant lines it is unusable Uninstalled and installed 2.0.49 and am able to work, until the autoupdate will break me again.

I'm experiencing the same thing. The first prompt works mostly fine, but after that, it becomes slow, sometimes even unusable.

2.0.50 introduced this bug.
reverted to 2.0.49

2.0.50 is absolutely unusable on windows. 5 min tasks can take up to 2 hours.

Downgrade with auto update disabled, for anyone interested.

Complete Setup Process
STEP 1: Ensure Hosts File is Unblocked

Open Command Prompt as Administrator
notepad C:\Windows\System32\drivers\etc\hosts
Delete this line if present: 127.0.0.1 registry.npmjs.org
Save and close
Verify: ping registry.npmjs.org (should show real IP)

--------------------------------------------------------------------------------------------------------

STEP 2: Uninstall Global Version
cmdnpm uninstall -g @anthropic-ai/claude-code

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STEP 3: Close Any Running Claude Code

Check Task Manager
End any node.exe processes running Claude
Close Command Prompt windows with Claude

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STEP 4: Clean Local Install Directory
cmdcd C:\claude-local
rmdir /S /Q node_modules
del package-lock.json

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STEP 5: Install Old Stable Version Locally
cmdnpm install @anthropic-ai/claude-code@2.0.35
Wait for "added 2 packages"

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STEP 6: Block Auto-Update

Open Command Prompt as Administrator
notepad C:\Windows\System32\drivers\etc\hosts
Add: 127.0.0.1 registry.npmjs.org
Save and close
Verify: ping registry.npmjs.org (should show 127.0.0.1)

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STEP 7: Run Claude Code
cmdcd C:\claude-local
node node_modules\@anthropic-ai\claude-code\cli.js

OR Create Easy Launcher
Simple Batch File

Create the file:
cmd notepad C:\claude-local\claude.bat
Paste this into Notepad:
batch @echo off
node C:\claude-local\node_modules\@anthropic-ai\claude-code\cli.js %*

Save and close
Now you can run it like this:
cmd C:\claude-local\claude.bat

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Keep both versions simultaneously
How to Keep Old + New Version:
When the new fixed version comes out:
Option 1: Global Install
Temporarily remove hosts block

cmd notepad C:\Windows\System32\drivers\etc\hosts
Delete the 127.0.0.1 registry.npmjs.org line, save

Install new version globally
cmd npm install -g @anthropic-ai/claude-code

Add hosts block back (Same file, add the line back)
Now you have BOTH:

Old stable: C:\claude-local\claude.bat (runs 2.0.35)
New version: claude (runs latest)
Both blocked from auto-updating

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Create Desktop Shortcut:
Drag and Drop

Open File Explorer
Navigate to C:\claude-local
Find claude.bat
Right-click, create shortcut and cut to your Desktop

@ronanocearbhaill-ui
no need for all the ceramony
just use the native windows version (why use node?) and set
"env": {
"DISABLE_AUTOUPDATER": 1
}

and/or: "autoUpdates": false

If you can download an old version that way then go ahead.

2.0.50 is insanely unbearably slow. I tried all the cleaning tips, but no matter what, 2-3 prompts in things would grind to a halt.
Downgrading to 2.0.49 was the trick.

If you can download an old version that way then go ahead.

@ronanocearbhaill-ui
https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/2.0.49/win32-x64/claude.exe

Just to further pinpoint the regression window: I encountered the same severe lag and total terminal input freeze starting with v2.0.46 (and v2.0.50), on Windows 11, tested both natively and in the CLI. Clean reinstalls/fresh configs and disabling auto-updates did not help. However, rolling back to v2.0.36 completely resolves all lag and freezing for me: performance is flawless, even in long sessions. So the underlying bug for input/copy-paste lockup appears between 2.0.36 and 2.0.46.

Hope this helps developers identify the exact regression window and prioritize a fix.

Just to further pinpoint the regression window: I encountered the same severe lag and total terminal input freeze starting with v2.0.46 (and v2.0.50), on Windows 11, tested both natively and in the CLI. Clean reinstalls/fresh configs and disabling auto-updates did not help. However, rolling back to v2.0.36 completely resolves all lag and freezing for me: performance is flawless, even in long sessions. So the underlying bug for input/copy-paste lockup appears between 2.0.36 and 2.0.46. Hope this helps developers identify the exact regression window and prioritize a fix.

how did u disable autoupdate ? On windows..

@michalss

Settings -> Search for: Edit the System Environment variables -> Environment Variables -> New system variable -> name: DISABLE_AUTOUPDATER value: 1.

Then:

npm install -g @anthropic-ai/claude-code@2.0.49

Same here. Even updated to preview 7.6.0 powershell and reinstalled completely, deleted all .claude folders, all settings, all history... Still nightmare slow and its not the model, its the client that freezes...
Likely related to bun memory issues as always because closing and running a fresh chat gives you 5-10 minutes of normal speed.

> Just to further pinpoint the regression window: I encountered the same severe lag and total terminal input freeze starting with v2.0.46 (and v2.0.50), on Windows 11, tested both natively and in the CLI. Clean reinstalls/fresh configs and disabling auto-updates did not help. However, rolling back to v2.0.36 completely resolves all lag and freezing for me: performance is flawless, even in long sessions. So the underlying bug for input/copy-paste lockup appears between 2.0.36 and 2.0.46. > Hope this helps developers identify the exact regression window and prioritize a fix. how did u disable autoupdate ? On windows..

Hi,

I did it in a couple of places to make sure because it's not especially obvious. I added this -
"autoUpdates": false

• after -
• "defaultMode": "bypassPermissions" -

to my ~/.calude/settings.json

I also temporarily set a system-wide value for the updater, my research suggested that Claude uses:

[System.Environment]::SetEnvironmentVariable("DISABLE_AUTOUPDATER", "1", "User")

Do your own research on the updater environment variable though in relation to your specifc system. Everything else seems to still update fine for me. Those two changes have completely worked.
This is what the /Doctor command now shows:

/Doctor

Diagnostics
└ Currently running: npm-global (2.0.36)
└ Auto-updates: false

Good luck, I plan to stay on 2.0.36 until this issue is closed (or I switch to Antigravity)

Claude Code (a terminal application) consumes 700 MB when idle on my system. That's about the same as Visual Studio 2022 Community with a loaded WPF project. In the performance monitor, I see it jumping from 700 to 1000 MB when running bash commands and going back to 700.

Not great. It's really gotten worse from version to version.

Thanks all for reporting! So sorry for the slowness here. We're aware of these issues and the Claude Code team is looking into it 🙏

@gomes0202 are you still seeing the Could not load the \"sharp\" module error? What triggered that error?

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