When was GPT-5-Codex released?

GPT-5-Codex was released by OpenAI on Monday, Sep 15 2025.

Who made GPT-5-Codex?

GPT-5-Codex was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

What benchmark scores did GPT-5-Codex get?

GPT-5-Codex reports 1 tracked benchmark score — BullshitBench v2: 39%. Scores are the figures published at release by OpenAI.

Is GPT-5-Codex open source?

No. GPT-5-Codex 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-Codex?

OpenAI's previous tracked release was GPT-5 Pro on Aug 7 2025, 39 days earlier. It was followed by GPT-5-Codex-Mini on Nov 7 2025.

GPT-5-Codex

Released Sep 15 2025

GPT-5-Codex is an AI model released by OpenAI on Monday, Sep 15 2025, 39 days after GPT-5 Pro. Benchmark results (shown below) cover BullshitBench v2.

Benchmarks

BullshitBench v2

39%

#37 of 77

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GPT-5-Codex

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Frequently asked questions

: GPT-5-Codex was released by OpenAI on Monday, Sep 15 2025.
: GPT-5-Codex was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.
: GPT-5-Codex reports 1 tracked benchmark score — BullshitBench v2: 39%. Scores are the figures published at release by OpenAI.
: No. GPT-5-Codex 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 Pro on Aug 7 2025, 39 days earlier. It was followed by GPT-5-Codex-Mini on Nov 7 2025.