When was GPT-5.1-Codex-Max released?

GPT-5.1-Codex-Max was released by OpenAI on Wednesday, Nov 19 2025.

Who made GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

Is GPT-5.1-Codex-Max open source?

No. GPT-5.1-Codex-Max is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

What came before and after GPT-5.1-Codex-Max?

OpenAI's previous tracked release was GPT-5.1 on Nov 12 2025, 7 days earlier. It was followed by GPT-5.2 on Dec 11 2025.

GPT-5.1-Codex-Max

Released Nov 19 2025

GPT-5.1-Codex-Max is an AI model released by OpenAI on Wednesday, Nov 19 2025, 7 days after GPT-5.1.

Available from


Azure	$1.25	$10.00	400K

USD per 1M tokens

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Frequently asked questions

: GPT-5.1-Codex-Max was released by OpenAI on Wednesday, Nov 19 2025.
: GPT-5.1-Codex-Max was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.
: No. GPT-5.1-Codex-Max is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.
: OpenAI's previous tracked release was GPT-5.1 on Nov 12 2025, 7 days earlier. It was followed by GPT-5.2 on Dec 11 2025.