gpt-5.1-codex
GPT-5.1 Codex (OpenAI)
Yes — GPT-5.1 Codex is retired. OpenAI deprecated it on April 22, 2026 and shut it down on July 23, 2026; API requests to it now fail. The recommended replacement is GPT-5.3 Codex.
The second-generation Codex model, and the one most coding agents shipped against through late 2025. Retired July 23, 2026 alongside gpt-5-codex, gpt-5.1-codex-max, gpt-5.1-codex-mini and gpt-5.2-codex — four generations of the same line, gone on one day.
The facts
| Provider | OpenAI |
|---|---|
| Model id | gpt-5.1-codex |
| Released | — |
| Deprecated | April 22, 2026 |
| Shutdown | July 23, 2026 · 7 days ago |
| Status | Retired |
| Last verified | July 30, 2026 |
What to use instead
gpt-5.3-codex is the current hosted Codex model. Given how fast this line turns over, pin it and set a calendar reminder rather than assuming a long life.
What parameters gpt-5.3-codex accepts on modelparams.dev
Change the id
In most cases the migration is one string. Check the parameter differences before you ship — newer models drop older sampling knobs more often than they add them.
- "model": "gpt-5.1-codex"
+ "model": "gpt-5.3-codex"
Frequently asked questions
- When did OpenAI GPT-5.1 Codex shut down?
- OpenAI GPT-5.1 Codex shut down on July 23, 2026. API requests to it fail from that date onward.
- What replaces OpenAI GPT-5.1 Codex?
- OpenAI recommends GPT-5.3 Codex (`gpt-5.3-codex`) as the replacement for OpenAI GPT-5.1 Codex. gpt-5.3-codex is the current hosted Codex model. Given how fast this line turns over, pin it and set a calendar reminder rather than assuming a long life.
- Is OpenAI GPT-5.1 Codex still available?
- No. OpenAI GPT-5.1 Codex is retired and no longer served — it was shut down on July 23, 2026. Calls to it return an error.
- How do I migrate from OpenAI GPT-5.1 Codex to gpt-5.3-codex?
- Swap the model id in your API call: replace "gpt-5.1-codex" with "gpt-5.3-codex". gpt-5.3-codex is the current hosted Codex model. Given how fast this line turns over, pin it and set a calendar reminder rather than assuming a long life.
Sources
- OpenAI API deprecations · developers.openai.com · accessed July 30, 2026
Found something wrong? The data is one YAML file — edit it on GitHub.
This page, for machines
Drop the badge in a README so it turns red the day this model is retired:
[](https://modeldeprecations.dev/openai/gpt-5.1-codex)