Welcome GPT OSS, the new open-source model family from OpenAI!

Back to Articles Welcome GPT OSS, the new open-source model family from OpenAI! Published August 5, 2025 Update on GitHub Upvote 510 +504 Vaibhav Srivastav reach-vb Follow Pedro Cuenca pcuenq Follow Lewis Tunstall lewtun Follow Clem 🤗 clem Follow Matthew Carrigan Rocketknight1 Follow Clémentine Fourrier clefourrier Follow Célina Hanouti celinah Follow Lucain Pouget Wauplin Follow Marc Sun marcsun13 Follow Simon Pagezy pagezyhf Follow Ákos Hadnagy ahadnagy Follow Joao Gante joaogante Follow GPT OSS is a hugely anticipated open-weights release by OpenAI, designed for powerful reasoning, agentic tasks, and versatile developer use cases. It comprises two models: a big one with 117B parameters (gpt-oss-120b), and a smaller one with 21B parameters (gpt-oss-20b). Both are mixture-of-experts (MoEs) and use a 4-bit quantization scheme (MXFP4), enabling fast inference (thanks to fewer active parameters, see details below) while keeping resource usage low. The large model fits on a single H100 GPU, while the small one runs within 16GB of memory and is perfect for consumer hardware and on-device applications. To make it even better and more impactful for the community, the models are licensed under the Apache 2.0 license, along with a minimal usage policy: We aim for our tools to be used safely, responsibly, and democratically, while maximizing your control over how you use them. By using gpt-oss, you agree to comply with all applicable law. According to OpenAI, this release is a mean...