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Anthropic Google OpenAI

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Anthropic 29 Google 24 OpenAI 103
OpenAI gpt-5.1-codex-max

GPT-5.1 Codex Max (OpenAI)

Retired

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.

The facts

Provider OpenAI
Model id gpt-5.1-codex-max
Released —
Deprecated April 22, 2026
Shutdown July 23, 2026 · 7 days ago
Status Retired
Last verified July 30, 2026

What to use instead

OpenAI GPT-5.3 Codex gpt-5.3-codex Provider-recommended Active

There is no separate -max id in the 5.3 Codex generation; the capability moved into the base model.

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-max"
+ "model": "gpt-5.3-codex"

Frequently asked questions

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

Found something wrong? The data is one YAML file — edit it on GitHub.

This page, for machines

JSON Markdown Badge JSON

Drop the badge in a README so it turns red the day this model is retired:

[![gpt-5.1-codex-max](https://img.shields.io/endpoint?url=https://modeldeprecations.dev/badge/openai/gpt-5.1-codex-max.json)](https://modeldeprecations.dev/openai/gpt-5.1-codex-max)

Other OpenAI models

All OpenAI deprecations →

How to use this site

The full guide, in Markdown. Copy it and hand it to a coding agent verbatim.

# How to use modeldeprecations.dev

[modeldeprecations.dev](https://modeldeprecations.dev) answers one question per model: is it deprecated,
when does it shut down, and what replaces it. Every date on the site is cited to the
provider's own documentation, with the date we last checked it.

Three lifecycle states are used, matching the providers' own vocabulary:

- **active** — still supported, no deprecation announced.
- **deprecated** — the provider has announced it is going away. It still answers requests.
- **retired** — API access is gone. Requests fail.

A model can be active *and* carry a shutdown date: Anthropic publishes a
"not sooner than" date and Google publishes an earliest shutdown date for models
that are current and fully supported. Those are reported as scheduled shutdowns,
not deprecations, because that is what the provider actually committed to.

## Check one model

```bash
curl https://modeldeprecations.dev/api/v1/models/openai/gpt-4-32k.json
```

Or fetch the page as Markdown, which includes the answer, the dates and the sources:

```bash
curl https://modeldeprecations.dev/openai/gpt-4-32k.md
```

## Full catalog

```bash
curl https://modeldeprecations.dev/api/v1/models.json
```

Ids are `provider/model`. Dated snapshots (`gpt-4-32k-0613`) are listed as aliases of
their canonical entry rather than as separate records.

Each entry carries `computed_status`, the lifecycle state recomputed against the build
date — so a model whose shutdown has passed reads `retired` without anyone editing data.

## Badges

A shields.io endpoint per model, for READMEs that should go red when a model dies:

```
https://img.shields.io/endpoint?url=https://modeldeprecations.dev/badge/openai/gpt-4-32k.json
```

## Calendar and changelog

- Subscribe to every shutdown date: https://modeldeprecations.dev/calendar.ics
- Changelog RSS: https://modeldeprecations.dev/changelog.xml

## JSON Schema

```bash
curl https://modeldeprecations.dev/api/v1/schema.json
```

## Contribute

Data lives in YAML under `models/{provider}/{model}.yaml` in the
[GitHub repo](https://github.com/mnfst/modeldeprecations.dev). Every lifecycle date needs a source URL; CI rejects a
date without one. Open a PR.

## For agents

- Machine-readable overview: https://modeldeprecations.dev/llms.txt
- This guide plus every model inline: https://modeldeprecations.dev/llms-full.txt
- Any page also exists as Markdown: append `.md` to a model URL.
- In a browser, this site registers a **WebMCP** tool on `navigator.modelContext`:
  `check_model_deprecation`, `list_shutdowns`, `find_replacement`, and `get_usage_guide`.
- Parameters each model accepts are catalogued on the sibling site, https://modelparams.dev.