Input lag when editing in workspace

[Wolfmare]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Hi,

I’m experiencing noticeable input lag when typing or editing files in Cursor with my project open. The same folder opened in Antigravity shows no lag, so the issue appears to be specific to Cursor.

Environment

• Windows 10
• Single folder workspace (path shown correctly in the bottom-left of Cursor)
• Codebase Indexing: 189 files (so the codebase is small and ignore files are applied)

What I’ve already tried (no improvement)

1. Ignore files

• Added a .cursorignore at project root (node_modules, dist, .agent tmp folders, SaveData, logs, cache, etc.).
• Synced the same patterns in .gitignore.
• Created a .cursorindexingignore with the same exclusions.
• Result: index went down to 189 files, but lag when typing remained.

2. Index and workspace

• Delete Index, then Sync: no change (when the index was still large).
• Restarted Cursor: no change.
• Restarted the PC: no change.
• Removed the folder from the workspace and re-added it (Open Folder): still 189 files, lag still there.
• Copied the entire project to a new path, created a new workspace for the copy: lag still there.

3. Editor / language features

• Disabled TypeScript (or related suggestions): no change.
• Enabled “Inline Suggest: Suppress Suggestions”: no change.

4. File watcher

• Added files.watcherExclude in .vscode/settings.json for node_modules, .git/objects, dist, and .agent tmp folders: no change.

Comparison

• Cursor with this workspace: lag when editing.
• Antigravity with the same folder as workspace: no lag.
  So the project and machine are fine; the lag seems tied to Cursor’s behavior with this workspace.

Has anyone else seen similar lag with a small indexed codebase (around 200 files), and are there any Cursor settings or known issues I should try or report?
Thanks.

Steps to Reproduce

Typing in any files like markdown inside a workspace (React/TypeScript/Vite app with node_modules present and a .cursorignore)

Operating System

Windows 10/11

Version Information

Version: 2.6.13 (user setup)
VSCode Version: 1.105.1
Commit: 60faf7b51077ed1df1db718157bbfed740d2e160
Date: 2026-03-06T06:17:49.499Z
Build Type: Stable
Release Track: Default
Electron: 39.6.0
Chromium: 142.0.7444.265
Node.js: 22.22.0
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.19045

Does this stop you from using Cursor

Yes - Cursor is unusable

[deanrie]

Hey, thanks for the detailed report and for all the troubleshooting you’ve already done. A few things can help narrow down the cause:

1. Test without extensions
   Run this from the command line:

   cursor --disable-extensions
   

   If the lag goes away, an extension is likely causing it. Then you can turn on Extension Monitor to find which one: Settings > Application > Experimental > Extension Monitor Enabled, then Ctrl+Shift+P > Developer: Open Extension Monitor.

2. Check Process Explorer
   Ctrl+Shift+P > Developer: Open Process Explorer. Look for anything using high CPU, especially extensionHost or ptyHost. A screenshot while the lag is happening would help a lot.

3. Check Developer Console
   Help > Toggle Developer Tools > Console. Do you see any errors, especially while typing?

4. If none of that shows anything, try cleaning globalStorage:

   • Fully close Cursor
   • Go to %APPDATA%\Cursor\User\globalStorage\
   • Rename state.vscdb and state.vscdb.backup to state.vscdb.old and state.vscdb.backup.old
   • Restart Cursor

Let me know what you find, especially the Process Explorer screenshot and whether disabling extensions helps.

[Wolfmare]

@deanrie

Developer: Open Extension Monitor

Thank you so much, Dean Rie, for taking the time to help and for suggesting the Extension Monitor — it led to a useful finding.

Quick clarification: I had already disabled all my extensions for the workspace, so I had not run the cursor --disable-extensions test before your message. I did run it afterward: the lag disappeared with --disable-extensions, which suggests something loaded as an extension (or built-in) is involved.

I then turned on Developer: Open Extension Monitor (Settings → Experimental → Extension Monitor Enabled, then Ctrl+Shift+P → Developer: Open Extension Monitor) and reproduced the lag with the monitor open. Nothing stood out in the Extension Monitor.

Here’s the odd part: the lag comes back after every Cursor restart. If I simply open the command palette (Ctrl+Shift+P) and close it right away without typing anything, the lag goes away for the rest of the session.

Thanks again.