# gpt-oss-120b

gpt-oss-120b is an AI model released by OpenAI on Aug 5 2025. It has 117B parameters, a 128k context window and open weight. At release it scored 11% on BullshitBench v2, 80.1% on GPQA Diamond and 62.4% on SWE-Bench Verified.

## Facts

| Field | Value |
| --- | --- |
| Model | gpt-oss-120b |
| Developer | OpenAI |
| Release date | Tuesday, Aug 5 2025 |
| Licensing | Open Weight |
| Parameters | 117B |
| Context window | 128k |

## Benchmark scores published at release

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| BullshitBench v2 | 11% | Lab | Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. |
| SWE-Bench Verified | 62.4% | Lab | Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. |
| Humanity's Last Exam (no tools) | 14.9% | Lab | Humanity's Last Exam — extremely hard expert questions across many subjects, written so you can't just look up the answer. “No tools” means the AI answers on its own. Higher is better. |
| Humanity's Last Exam (with tools) | 19% | Lab | Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better. |
| GPQA Diamond | 80.1% | Lab | Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. |
| MMLU | 90% | Lab | A 57-subject multiple-choice exam — history, law, medicine, maths — that was the standard measure of how much a model knows from 2020 until roughly 2024, when frontier scores crowded into the high 80s and labs moved on to harder tests. The scores here were published years apart under different testing setups, so read them as a historical record rather than a like-for-like ranking. Higher is better. |

## About gpt-oss-120b

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.

## Questions and answers

### When was gpt-oss-120b released?

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

### Who made gpt-oss-120b?

gpt-oss-120b was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

### What benchmark scores did gpt-oss-120b get?

gpt-oss-120b reports 6 tracked benchmark scores — BullshitBench v2: 11%; SWE-Bench Verified: 62.4%; Humanity's Last Exam (no tools): 14.9%; Humanity's Last Exam (with tools): 19%; GPQA Diamond: 80.1%; MMLU: 90%. Scores are the figures published at release by OpenAI.

### What is the context window of gpt-oss-120b?

gpt-oss-120b has a context window of 128k. That is the maximum amount of input plus output the model can hold in a single request.

### How many parameters does gpt-oss-120b have?

gpt-oss-120b is reported at 117B parameters.

### Is gpt-oss-120b open source?

Partly. gpt-oss-120b is an open-weight model: the trained weights are free to download and run locally or on your own infrastructure, but the training data and code are not fully released and the license may restrict some commercial uses. It is not open source in the strict sense.

### What came before and after gpt-oss-120b?

OpenAI's previous tracked release was o3-pro on Jun 10 2025, 56 days earlier. It was followed by gpt-oss-20b on Aug 5 2025.


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Canonical page: https://aireleasetracker.com/model/openai/gpt-oss-120b
Full dataset: https://aireleasetracker.com/llms-full.txt · JSON: https://aireleasetracker.com/models.json
Source: AI Release Tracker (https://aireleasetracker.com). Benchmark scores are the figures published by the releasing lab at launch.