Cursor is very slow and keeps becoming unresponsive

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Cursor is very slow and keeps becoming unresponsive.

Steps to Reproduce

It suddenly became very slow. No matter which model I switch to, it’s slow. Even a simple ‘hello’ takes a very long time to respond.

Operating System

Windows 10/11

Version Information

Version: 3.1.17 (user setup)VSCode Version: 1.105.1Commit:fce1e9ab7844f9ea35793da01e634aa7e50bce90Date:2026-04-19T19:33:58.189Z(3 天前)
Layout: editorBuild Type: StableRelease Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265Node.js: 22.22.1
W8: 14.2.231.22-electron.0OS: Windows NT x64 10.0.19045

For AI issues: which model did you use?

composer2 fast

Does this stop you from using Cursor

No - Cursor works, but with this issue

4

Right now, it can only give a simple reply like ‘hello’, but even that takes a very long time to respond. For other questions, it takes even longer or becomes completely unresponsive.

6

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7

Hey, I saw the diagnostics screenshot. Chat is crashing with the error “streaming responses are being buffered by a proxy”. This error is misleading. You do not actually have a proxy. The real issue is high latency to our streaming servers. api2.cursor.sh in China and India goes directly to AWS US without a Cloudflare edge, so it can be slow. Your backend is responding fine, and the slowness is client-side buffering.

This is a known issue and we do not have an ETA for a fix yet. A workaround that definitely worked for a user with the same symptom is here: Chat & Agent streaming blocked — proxy buffering error (India, mobile network)

  • Disable HTTP/2: Ctrl+, → search HTTP/2 → turn on Disable HTTP/2 → fully restart Cursor, not just close the window
  • If that does not help, try switching DNS to 1.1.1.1 or 8.8.8.8
  • As a last option, try Cloudflare WARP: https://one.one.one.one/ It is free and routes traffic through Cloudflare edge nodes

Let me know if disabling HTTP/2 helps. For most users, that is enough.

8

After disabling HTTP/2, it’s back to normal.

9

Cloudflare WARP can also solve the problem.

10

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