gpt-oss-20b
gpt-oss-20b is an OpenAI model, released August 2025. It has a 131,072-token context window and up to 131,072 output tokens. It supports function calling, structured outputs and reasoning.
- Status
- Active
- Released
- August 2025
- Shutdown
- none announced
- Replacement
- —
No deprecation or shutdown date has been announced as of October 15, 2026.
Benchmarks
Scores as each source published themNo comparison. Pick a model to see the difference on each benchmark.
Arena
| Arena | gpt-oss-20b | Rank | Date | Source |
|---|---|---|---|---|
TextBy category
| 1317 ±6 | 266 of 415 10,421 votes | Oct 13, 2026 | source |
| Text: Coding | 1368 ±13 | 248 of 410 2,112 votes | Oct 13, 2026 | source |
Rated as gpt-oss-20b. Ratings come from people voting between two anonymous answers; Text is style-controlled, as on arena.ai. Data: Arena (arena.ai), CC BY 4.0.
Epoch AI
| Benchmark | gpt-oss-20b | Setting | Run | Source |
|---|---|---|---|---|
GPQA DiamondOther settings
| 60.8% | medium effort | Aug 27, 2026 | source |
OTIS Mock AIME 2024-2025Other settings
| 65.3% | medium effort | Aug 27, 2026 | source |
Run independently by Epoch AI. Data: Epoch AI, Capabilities & benchmarking (epoch.ai/benchmarks), CC BY.
On cloud platforms
All platform dates| Platform | Platform ID | State | Shutdown | Time left | Replacement | Source |
|---|---|---|---|---|---|---|
| Amazon Bedrock | openai.gpt-oss-20b-1:0 | Active | not before Aug 5, 2026 | — | source | |
| Google Cloud Vertex AI | gpt-oss-20b-maas | Deprecated | Oct 21, 2026 | 6 days | Self-deploy GPT OSS on Model Garden | source |
Read daily from each platform's own pages. The shutdown date and countdown on this page use OpenAI's own date. Time left counts to 00:00 UTC on the shutdown date, which is the evening before in ET.
Features
Compare models| Feature | Value | Since | Source |
|---|---|---|---|
| Structured outputsThe model can be held to a JSON schema you supply, so every reply parses without retries or cleanup. | Supported | in place when tracking began (October 7, 2026) | source |
| Function callingAlso called tool use. You describe functions; the model replies with a function name and arguments for your code to run, then uses the result. | Supported | in place when tracking began (October 7, 2026) | source |
| Batch APISend many requests as one job that runs in the background, usually finished within 24 hours, at a lower price than live requests. | Supported | in place when tracking began (October 7, 2026) | source |
| Reasoning / thinkingThe model can work through a problem step by step before it answers: usually better answers to hard questions, at the cost of more tokens and time. | Supported | in place when tracking began (October 7, 2026) | source |
| Fine-tuningYou can train your own version of the model on your examples through the company's API, then call it like any other model. | Not supported | in place when tracking began (October 7, 2026) | source |
| Context windowThe most the model can work with in one request, in tokens: your prompt, conversation history and files. A token is about three-quarters of an English word. | 131,072 tokens | in place when tracking began (October 7, 2026) | source |
| Max output tokensThe longest reply the model can write in one response, in tokens. A token is about three-quarters of an English word. | 131,072 tokens | in place when tracking began (October 7, 2026) | source |
Not published by OpenAI: Prompt caching, Image input, PDF input, Built-in web search, temperature parameter, top_p parameter, logprobs.
Price history
USD per 1M tokens, standard tierNo price history yet.
Prices
USD per 1M tokens, every type and band, by tierNo published prices.
Changelog
Changes we detected on OpenAI's pagesNo changes recorded yet.
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Last checked · Sources: OpenAI deprecations, OpenAI pricing, OpenAI models