When was GPT-5.3-Codex-Spark released?

GPT-5.3-Codex-Spark was released by OpenAI on Thursday, Feb 12 2026.

Who made GPT-5.3-Codex-Spark?

GPT-5.3-Codex-Spark was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

What is the context window of GPT-5.3-Codex-Spark?

GPT-5.3-Codex-Spark has a context window of 128k. That is the maximum amount of input plus output the model can hold in a single request.

Is GPT-5.3-Codex-Spark open source?

No. GPT-5.3-Codex-Spark 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-5.3-Codex-Spark?

OpenAI's previous tracked release was GPT-5.3-Codex on Feb 5 2026, 7 days earlier. It was followed by GPT-5.4 on Mar 5 2026.

GPT-5.3-Codex-Spark

Released Feb 12 2026

GPT-5.3-Codex-Spark is an AI model released by OpenAI on Thursday, Feb 12 2026, 7 days after GPT-5.3-Codex. It has a 128k token context window.

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GPT-5.3-Codex-Spark

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Frequently asked questions

: GPT-5.3-Codex-Spark was released by OpenAI on Thursday, Feb 12 2026.
: GPT-5.3-Codex-Spark was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.
: GPT-5.3-Codex-Spark has a context window of 128k. That is the maximum amount of input plus output the model can hold in a single request.
: No. GPT-5.3-Codex-Spark 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-5.3-Codex on Feb 5 2026, 7 days earlier. It was followed by GPT-5.4 on Mar 5 2026.