gpt-oss-120b at a glance
The Apache 2.0 gpt-oss models are mixture-of-experts reasoning models: the 120b nears o4-mini on core reasoning on a single 80 GB GPU, and the 20b matches o3-mini and runs in 16 GB of memory.
What changed with gpt-oss-120b
On August 5, 2025, OpenAI released gpt-oss-120b and gpt-oss-20b, open-weight language models under the Apache 2.0 license. Both are mixture-of-experts transformers: the 120b has 117 billion total and 5.1 billion active parameters, the 20b has 21 billion total and 3.6 billion active, and both support 128K context.
OpenAI said gpt-oss-120b reaches near-parity with o4-mini on core reasoning benchmarks while running on a single 80 GB GPU, and gpt-oss-20b performs similarly to o3-mini and can run on devices with 16 GB of memory. They support low, medium and high reasoning effort, full chain-of-thought access, tool use such as web search and Python, and the Responses API format.
gpt-oss-120b in numbers
Values are copied from the linked source on the date shown. They are not IA Compa measurements.
- Context windowas of · Source for Context window: openai.com (opens in a new tab)
- 128K tokens
How it compares
Models that were current when this was published (released in the six months before it, newest version of each line), so these figures are from that time. Under each chart is the current best. (Models)
Current best (as of Nov 6, 2026): GPT-6 Cyber, 1.05M tokens
Where to compare gpt-oss-120b
Independent leaderboards and official resources for comparing this model yourself. Rankings change often; each site shows its own current data.
General leaderboards
Why gpt-oss-120b matters for businesses
For businesses, gpt-oss made it possible to run an OpenAI-grade reasoning model fully on your own hardware with a permissive license, a strong option for private deployments, regulated data and offline use.
Sources for this story
- Introducing gpt-oss (opens in a new tab)Official
OpenAI · openai.com
- openai/gpt-oss-120b (opens in a new tab)Official
Hugging Face · huggingface.co
- gpt-oss-120b model page (opens in a new tab)Benchmark
Artificial Analysis · artificialanalysis.ai
Last verified: . IA Compa summarizes public announcements for business readers. We are not affiliated with the companies mentioned. Always confirm details, pricing, and availability with the official source.
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