GPT-5.3-Codex-Spark is an AI model released by OpenAI on Feb 12 2026, 7 days after GPT-5.3-Codex. It is the 28th tracked release from OpenAI out of 31 total.
Its context window is 128k.
About OpenAI: Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.