Why does Codex live in the ChatGPT app now?
Welcome to Codex · lesson 3 of 12
Until the summer of 2026, Codex had its own separate app for your computer. On 9 July 2026, it was merged into the ChatGPT desktop app (official release notes). Desktop means your computer (Mac, Windows or, in preview, Linux), not the website and not your phone.
If you find online guides about “the Codex app”, they describe the old version.
The ChatGPT app now has three modes:
Chat: quick questions and conversations, like the ChatGPT you already know.Work: research and finished deliverables, such as documents, presentations or spreadsheets.Codex: building apps, with the files on your computer.
You switch modes from the ChatGPT dropdown menu.
Or with keyboard shortcuts: ⌃1, ⌃2, ⌃3 on a Mac (⌃ is the Control key) and Alt+1, Alt+2, Alt+3 on Windows (official list of shortcuts).
Codex mode keeps its own chat history, separate from the others.
In this course we work in Codex mode almost all the time. From here on we simply call it “the app” or “Codex”.