Codex CLI Font Randomly Changes
What version of Codex CLI is running?
codex-cli 0.98.0
What subscription do you have?
Plus
Which model were you using?
gpt-5.3-codex xhigh
What platform is your computer?
Microsoft Windows NT 10.0.19045.0 x64
What terminal emulator and version are you using (if applicable)?
Windows CMD
What issue are you seeing?
After Codex runs for a while, the font changes at some point. It seems random. Being alt-tabbed is not required to replicate the issue. I's been happening consistently for a few days now.
<img width="1736" height="825" alt="Image" src="https://github.com/user-attachments/assets/3c46cd63-f49b-4be7-b8b3-0bb5b3e5cd80" />
It's not a major problem, but the changed fonts are usually less readable.
I had it once when the font changed 2 times: The changed font changed again to something else which was even less readable.
What steps can reproduce the bug?
Just keep Codex running for a while. A long planning phase followed by a long implementation session seems to consistently replicate it for me.
What is the expected behavior?
I would expect a stable font.
Additional information
_No response_
6 Comments
For the record, this is the usual font for me:
<img width="966" height="466" alt="Image" src="https://github.com/user-attachments/assets/f64c4fd3-6233-41b9-abf8-0a342c74ad34" />
The color of the text also seems to change when the bug occurs.
This sounds like it might be an issue with Windows CMD, not codex. I don't think we have many users who use Windows CMD. You might want to try switching to PowerShell and see if that works better for you.
@etraut-openai I was able to replicate the issue in PowerShell.
<img width="862" height="639" alt="Image" src="https://github.com/user-attachments/assets/3bb9dedb-6575-4835-b44f-3dd7f593dec4" />
when the bug occurs, the window gets resized down, and the font changes, just like in CMD.
the bug occurrence is not related to context window being filled, it can happen even at 0% context (right after I sent the prompt, as can be seen in the screenshot) .
once again for reference, here is the normal state in PowerShell:
<img width="943" height="499" alt="Image" src="https://github.com/user-attachments/assets/60215c59-1f8d-4396-90d8-bda908e8a7d2" />
I also experience this (0.116.0) running from admin powershell. It starts with the default Consolas 16, then changes to Raster Fonts 8 x 12. If I change the session back to the default, it'll flip back to Raster Fonts pretty quickly.
https://github.com/user-attachments/assets/a690cc4e-7136-4104-9b22-65c47bdbae14
It seems like the "modern" Windows Terminal doesn't have this issue, so try switching to that instead of powershell.
I stumpled upon someone having the same problem on a different OS, with a different tool using a different terminal emulator: https://github.com/jesseduffield/lazygit/issues/5292
He apparently solved it by switching from C.UTF8 to en_GB.UTF8
As for me, I've switched to Linux with Alacritty and haven't had the issue ever since.