Codex desktop app high CPU and rapid memory growth on startup (macOS)

Resolved 💬 5 comments Opened Feb 9, 2026 by Skies-syx Closed Feb 17, 2026

💡 Likely answer: A maintainer (etraut-openai, contributor) responded on this thread — see the highlighted reply below.

What version of the Codex App are you using (From “About Codex” dialog)?

Version 260208.1016 (571)

What subscription do you have?

plus

What issue are you seeing?

The CPU of the Mac has significantly increased, and Codex has crashed.

What steps can reproduce the bug?

Execute: npx skills add openclaw/openclaw
Open code X
Observe that the CPU usage in the activity monitor is 90%, and finally the codex exits.

What is the expected behavior?

The codex is operating stably.

Additional information

_No response_

View original on GitHub ↗

5 Comments

Skies-syx · 6 months ago

The following is the conclusion obtained through the troubleshooting process using VSCode Codex.

Subject: Codex desktop app high CPU and rapid memory growth on startup (macOS)

Hi team,

I’m seeing persistent high CPU usage when launching Codex desktop.

Environment:

App: Codex desktop
Version: 260208.1016
OS: macOS 15.6 (24G84)
Device: Apple Silicon (arm64)

Symptoms:

High-CPU process is /Applications/Codex.app/Contents/MacOS/Codex (not codex app-server).
CPU repeatedly spikes to about 45%–100% after startup.
Memory (RSS) grows quickly after launch (example: ~281MB -> ~767MB within ~8 seconds in one sample).
Logs show repeated [desktop-notifications] service starting.
In earlier runs, logs also showed:

ResizeObserver loop completed with undelivered notifications.

What I already tried:

Backed up and reset local Codex desktop state/logs.
Relaunched and re-tested.
Issue still reproducible.

Diagnostic package attached:

/tmp/codex_diagnostic_20260209-162414.zip

Please help investigate startup rendering/notification loop behavior and memory growth.

Thanks.

codex_diagnostic_20260209-162414.zip

garethmcnicol-lendingcrowd · 6 months ago

This app is useless. 'It doesn't work on Mac Silicon, known issue' [has only been released for macos]

Do better, guys. Don't give us AI Slop and call it groundbreaking; it's a bad look for you. You need to do some _actual_ QA testing for this kind of slop.

Skies-syx · 6 months ago

I tried many methods but failed to escape this case

etraut-openai contributor · 6 months ago

We've made many improvements to memory usage and performance over the past week. Are you still seeing this problem with the latest version of the app?

maronk · 6 months ago

Can confirm same issue here MacBook M4 Pro with 48GB RAM - app is slow and very unresponsive / lagging when clicking, switching threads, runs high cpu and keeps spinning my fans which are seldomly heard otherwise.