Diff panel shows ~3 million changed lines, causes severe performance issues and freezes on macOS
Open 💬 9 comments Opened Feb 9, 2026 by menesekinci
💡 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)?
260208.1016 (571)
What subscription do you have?
Plus
What issue are you seeing?
<img width="173" height="58" alt="Image" src="https://github.com/user-attachments/assets/6f42b3ee-6499-4fa3-9135-590c21fa5953" />
I’m experiencing a serious performance issue with the Codex macOS desktop app. The Diff panel incorrectly shows around 3 million modified lines of code, even though the actual changes are nowhere near that size.
Because of this:
- The app becomes extremely slow and unresponsive
- CPU and memory usage spike heavily
- The UI frequently freezes
- The issue does not resolve itself and persists across usage
The Diff panel seems to get into a broken state where it thinks millions of lines have changed, and once this happens, the application becomes almost unusable.
Expected behavior:
- Diff panel should accurately reflect the actual number of changed lines
- App should remain responsive and performant
Actual behavior:
- Diff panel shows millions of changed lines incorrectly
- App becomes very heavy, slow, and frequently freezes
Environment:
- OS: macOS (Apple Silicon)
- App: Codex macOS desktop app
- Happens consistently once triggered
This is very frustrating and makes the app difficult to use for real development work. Any guidance or fix would be appreciated.
What steps can reproduce the bug?
- Open a project in the Codex macOS desktop app
- Make normal code changes (small or medium sized)
- Open the Diff panel
- The Diff panel reports ~3,000,000 changed lines
- App starts lagging badly and often freezes
What is the expected behavior?
_No response_
Additional information
_No response_
9 Comments
I'd like to add to this. Not experiencing the same issue but related.
<img width="788" height="738" alt="Image" src="https://github.com/user-attachments/assets/47c005cd-4710-4bfe-b84f-99fc7eb60172" />
As the conversation fills up with these diffs, the Electron Renderer process balloons in memory usage and the app becomes extremely sluggish over time. If you restart the app, load the same conversation, all of those cards are gone and memory usage returns to normal. I think if y'all make these cards disappear from the convo if the user doesn't press review or undo it will drastically improve performance.
the same:
<img width="184" height="45" alt="Image" src="https://github.com/user-attachments/assets/762d04e7-9ef8-4c26-bb46-6510febca48e" />
when i start a new project, this happens and i can not use this app because of high performance issues(nearly freezing)
also put my activity monitor screenshot:
<img width="1186" height="188" alt="Image" src="https://github.com/user-attachments/assets/93416e5f-96dc-412f-97fe-dcedbb2d6ffc" />
note: different with @robertmsale issue, i just opened a new git repo. After I delete this project the issue disappeared
We've fixed a bunch of perf issues over the past week. Are you still seeing this problem with the latest version?
For me, all performance issues are gone :) memory usage is not growing out of control with any conversations.
Indeed; I see significant improvements regarding this issue.
I'd like to re-open as this is still an issue on the latest version as of today: Version 26.224.1209 (697)
<img width="209" height="58" alt="Image" src="https://github.com/user-attachments/assets/e0326b10-1812-4230-90b2-73c1b8017e1d" />
Not sure if that's the reason but app freezes/scrolls at ~1fps sometimes and generally feels super sluggish.
I also think that Codex is causing syspolicyd to go crazy and use 100% cpu which is likely contributing to the sluggishness. Looking at open files of syspolicyd shows a very long list involving "Codex" when the cpu spikes happen.
<img width="551" height="557" alt="Image" src="https://github.com/user-attachments/assets/12f35efa-e8c4-4f71-80c9-409f354f519e" />
And if I run:
sudo fs_usage -w -f execThen I see a gazillion lines of posix_spawn referencing my project directory. To clarify, the path below is NOT a binary, it's the directory at the root of my project.
12:15:23.856097 posix_spawn [ 2] </path/to/my/project>
It seems that Codex is doing this in a loop many times per second which triggers syspolicyd to scan and cause high cpu usage?
Has anyone found a solution to this? I'm sitting here on March 17th still having this exact same issue where it's showing a crazy line diff in one of my repos and when I try to work in that repo it's running incredibly laggy and slow.
<img width="220" height="104" alt="Image" src="https://github.com/user-attachments/assets/74069752-f3d4-4abc-865b-d84244c721e5" />
April 15, the issues is still there. And codex made it even worse now, because clicking on a file link opens the side panel instead of VS Code like before, and that's when the whole app freezes.