gpt-oss-120bOpen Weight

Released

gpt-oss-120b is an AI model released by OpenAI on Tuesday, Aug 5 2025, 56 days after o3-pro. It is an open-weight model — the trained weights are available to download and run. It is a 117B parameter model with a 128k token context window. Benchmark results (shown below) cover MMLU, BullshitBench v2, SWE-Bench Verified, Humanity's Last Exam, and GPQA Diamond.

Available from

AkashML$0.03$0.17128Kbf16
CoreWeave$0.03$0.17128Kfp4
DeepInfra$0.037$0.17128Kbf16
DekaLLM$0.03$0.18128Kbf16
Crusoe$0.05$0.25128Kbf16
Novita$0.05$0.25128Kfp4
DigitalOcean$0.06$0.42128K
Mancer 2$0.055$0.50128Kfp8
BaseTen$0.10$0.50128Kfp4
DeepInfraturbo$0.15$0.60128Kbf16
Amazon Bedrockeu-west-1$0.15$0.60128K
Groq$0.15$0.60128K
Nebius$0.15$0.60128Kfp4
Phala$0.15$0.60128K
SiliconFlow$0.15$0.60128Kfp8
Parasail$0.10$0.75128Kfp4
Cerebras$0.35$0.75128Kfp16
DeepInfra$0.20$0.95128Kfp8
USD per 1M tokens

Benchmarks

Coding

SWE-Bench Verified
62.4%
#44 of 57

Reasoning & science

MMLU
90%
#1
Humanity's Last Exam
14.9%
no tools
19%
with tools
no tools
#21 of 22
with tools
#40 of 42
GPQA Diamond
80.1%
#35 of 59

Robustness

BullshitBench v2
12%
#69 of 77

About

gpt-oss-120b, released August 5, 2025 alongside the smaller gpt-oss-20b, was OpenAI's first open-weight language model since GPT-2 in 2019 — six years in which the company that popularised the term "open" shipped nothing downloadable. Both models came under Apache 2.0 with no usage restrictions and no commercial gate. The 120B is a mixture-of-experts design with about 5.1B parameters active per token, sized to fit on a single 80GB accelerator, while the 21B sibling was built to run on a high-end laptop.

The launch figures put it close to OpenAI's own mid-tier closed models: 80.1% on GPQA Diamond and 62.4% on SWE-Bench Verified, 90.0% on MMLU, and 14.9% on Humanity's Last Exam without tools, rising to 19.0% with them. OpenAI framed the release as a response to the Chinese open-weight wave — DeepSeek R1 and Kimi K2 had spent the preceding months setting the pace for freely downloadable models — and shipped it two days before GPT-5, which took the attention.

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Frequently asked questions

gpt-oss-120b was released by OpenAI on Tuesday, Aug 5 2025.

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44 tracked

2022

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