5.5

GPT-5.5 is now available in Codex as OpenAI's newest frontier model for complex coding, computer use, knowledge work, and research workflows.

GPT-5.5 in Codex

GPT-5.5 is the recommended choice for most Codex tasks when it appears in your model picker. It's especially useful for implementation, refactors, debugging, testing, validation, and knowledge-work artifacts.

To switch to GPT-5.5:

• In the CLI, start a new thread with:

  codex --model gpt-5.5

  Or use /model during a session.
• In the IDE extension, choose GPT-5.5 from the model selector in the composer.
• In the Codex app, choose GPT-5.5 from the model selector in the composer.

If you don't see GPT-5.5 yet, update the CLI, IDE extension, or Codex app to the latest version. During the rollout, continue using GPT-5.4 if GPT-5.5 is not yet available.

Browser use in the Codex app

The Codex app can now let Codex operate the in-app browser for local development servers and file-backed pages. Ask Codex to use the browser when it needs to click through a rendered UI, reproduce a visual bug, or verify a local fix inside the app.

Browser use runs through the bundled Browser plugin. In settings, you can manage the plugin and review allowed or blocked websites.

Automatic approval reviews

Codex can route eligible approval prompts through an automatic reviewer agent before the request runs. When configured, the Codex app shows an automatic review item with the review status and risk level, so you can see whether the reviewer approved, denied, stopped, or timed out before deciding.