We introduce gpt-oss-120b and gpt-oss-20b, two open-weight reasoning models available under the Apache 2. 0 license and our gpt-oss usage policy.
gpt-oss-safeguard-120b and gpt-oss-safeguard-20b are two open-weight reasoning models post-trained from the gpt-oss models and trained to reason from a provided policy in order to label content under that policy. In this report, we describe gpt-oss-safeguard’s capabilities and provide our baseline safety evaluations on the gpt-oss-safeguard models, using the underlying gpt-oss models as a baseline.
We’re releasing gpt-oss-120b and gpt-oss-20b—two state-of-the-art open-weight language models that deliver strong real-world performance at low cost. Available under the flexible Apache 2.
We’re releasing a research preview of OpenAI GPT‑4. 5, our largest and most knowledgeable model yet.
This system card outlines the comprehensive safety measures implemented for GPT‑5. 1-CodexMax.
GPT-5. 2 is the latest model family in the GPT-5 series.
OpenAI introduces gpt-oss-safeguard—open-weight reasoning models for safety classification that let developers apply and iterate on custom policies.
GPT‑5. 3-Codex is the most capable agentic coding model to date, combining the frontier coding performance of GPT‑5.
As the final model release of GPT-2’s staged release, we’re releasing the largest version (1. 5B parameters) of GPT-2 along with code and model weights to facilitate detection of outputs of GPT-2 models.