OpenAI: ‘Introducing gpt-oss’

OpenAI:

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 2.0 license, these models outperform similarly sized open models on reasoning tasks, demonstrate strong tool use capabilities, and are optimized for efficient deployment on consumer hardware. They were trained using a mix of reinforcement learning and techniques informed by OpenAI’s most advanced internal models, including o3 and other frontier systems.

The gpt-oss-120b model achieves near-parity with OpenAI o4-mini on core reasoning benchmarks, while running efficiently on a single 80 GB GPU. The gpt-oss-20b model delivers similar results to OpenAI o3‑mini on common benchmarks and can run on edge devices with just 16 GB of memory, making it ideal for on-device use cases, local inference, or rapid iteration without costly infrastructure. Both models also perform strongly on tool use, few-shot function calling, CoT reasoning (as seen in results on the Tau-Bench agentic evaluation suite) and HealthBench (even outperforming proprietary models like OpenAI o1 and GPT‑4o).

Simon Willison:

The long promised OpenAI open weight models are here, and they are very impressive. [...]

o4-mini and o3-mini are really good proprietary models — I was not expecting the open weights releases to be anywhere near that class, especially given their small sizes. That gpt-oss-20b model should run quite comfortably on a Mac laptop with 32GB of RAM.

★ Wednesday, 6 August 2025