codex - 💡(How to fix) Fix Add app-level UI scale setting for Codex Desktop on Windows

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

26.513.4821.0

What subscription do you have?

Plus

What platform is your computer?

Windows 10 Pro 25H2, OS build 26200.8457, x64

What issue are you seeing?

The Codex Desktop UI is too small for comfortable use on my Windows setup. Increasing Windows display scaling makes Codex usable, but it also affects every other application on the system.

My current Windows display scaling is 150%. Raising the system display scaling further makes Codex comfortable, but makes other apps too large. I would like a Codex-only UI scale setting.

This is slightly different from retaining the existing zoom level (#20763) or fixing broken zoom controls (#16761). The request is for a native Codex Desktop UI scale preference that behaves like an application-level scale setting and does not require changing the entire Windows display scale.

What steps can reproduce the bug?

1. Use Codex Desktop on Windows at 150% display scaling.
2. Observe that the Codex UI still appears smaller than desired.
3. Increase Windows display scaling further.
4. Codex becomes more comfortable, but all other Windows apps are also enlarged.
5. Try local workarounds:
   • Increasing Codex font sizes makes some text larger, but some UI areas become clipped or overlapped.
   • Chromium/Electron device scale flags such as --force-device-scale-factor enlarge the app, but break the floating avatar/pet overlay: the pet can only move within the upper-left portion of the screen, likely because desktop coordinate calculations no longer match the app scale.
   • CSS/page zoom can enlarge content, but causes clipping.
   • Chromium emulated viewport scaling can make the UI larger, but does not fill the window correctly and can leave blank space.
   • Windows per-app High DPI compatibility overrides do not appear reliable for the MSIX/Electron packaged Codex app.

What is the expected behavior?

Codex Desktop should provide a native app-level UI scale setting, for example:

• 100%
• 125%
• 150%
• 175%
• 200%

This setting should affect the whole Codex UI, including layout, text, controls, sidebars, input composer, and overlays, without affecting other Windows applications.

It should also preserve correct behavior for floating overlays such as the avatar/pet.

Additional information

Related issues:

• #20763: retain custom zoom level across launch
• #16761: zoom breaks controls
• #23024: Windows display scaling can affect composer layout

A built-in UI scale setting would avoid relying on system-wide display scaling or fragile launch-flag workarounds.