# OpenAI GPT-5.1 Codex Max — deprecation status

> Yes — GPT-5.1 Codex Max 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 largest Codex variant, built for repository-scale work where the model needed to hold an entire codebase in context. It lasted about eight months before being retired with the rest of the Codex line.

## Facts

| Field | Value |
| --- | --- |
| Provider | OpenAI |
| Model id | `gpt-5.1-codex-max` |
| Status | Retired |
| Deprecated | April 22, 2026 |
| Shutdown | July 23, 2026 (7 days ago) |
| Last verified | July 30, 2026 |

## Replacement

- **GPT-5.3 Codex** (`gpt-5.3-codex`) · recommended — https://modeldeprecations.dev/openai/gpt-5.3-codex
  - There is no separate -max id in the 5.3 Codex generation; the capability moved into the base model.
  - Parameters it accepts: https://modelparams.dev/models/openai/gpt-5.3-codex

```diff
- "model": "gpt-5.1-codex-max"
+ "model": "gpt-5.3-codex"
```

## FAQ

### When did OpenAI GPT-5.1 Codex Max shut down?

OpenAI GPT-5.1 Codex Max shut down on July 23, 2026. API requests to it fail from that date onward.

### What replaces OpenAI GPT-5.1 Codex Max?

OpenAI recommends GPT-5.3 Codex (`gpt-5.3-codex`) as the replacement for OpenAI GPT-5.1 Codex Max. There is no separate -max id in the 5.3 Codex generation; the capability moved into the base model.

### Is OpenAI GPT-5.1 Codex Max still available?

No. OpenAI GPT-5.1 Codex Max 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 Max to gpt-5.3-codex?

Swap the model id in your API call: replace "gpt-5.1-codex-max" with "gpt-5.3-codex". There is no separate -max id in the 5.3 Codex generation; the capability moved into the base model.

## Sources

- [OpenAI API deprecations](https://developers.openai.com/api/docs/deprecations) — accessed 2026-07-30

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Canonical page: https://modeldeprecations.dev/openai/gpt-5.1-codex-max
JSON: https://modeldeprecations.dev/api/v1/models/openai/gpt-5.1-codex-max.json