Field Guide · Week of 17 August 2026
gpt-oss 20B
OpenAI · United States · OpenAI
OpenAI’s first open weights since GPT-2. Built to run in 16 GB. Apache license. Very widely downloaded.
- Where it runs
- Runs on your computer
- Memory
- 16 GB (native 4-bit)
- Size
- 21B MoE · 3.6B active
- License
- Apache 2.0
Why it is on this week’s list
The name people already trust, in a size a laptop can hold. We still pick Gemma when the writing has to stay calm.
Use it when
You want an OpenAI-shaped voice on your own disk.
Skip it when
Regulated work where you prefer a non-OpenAI lineage.
Published scores
Scores as of 17 August 2026. A blank test is not a zero. We just will not invent it.
- GPQA Diamond
- 71.5*
- SWE-Bench Verified
- 60.7*
- LiveCodeBench
- —
- MMLU / MMLU-Pro
- 85.3*
- AIME
- —
- Humanity’s Last Exam
- 10.9*
OpenAI gpt-oss card (high) · 2025-08-05
No tools, high reasoning.
OpenAI gpt-oss card (high) · 2025-08-05
No public number we will stand behind.
OpenAI gpt-oss card (high) · 2025-08-05
No public number we will stand behind.
OpenAI gpt-oss card · 2025-08-05
No tools.