OpenAI: GPT OSS 20B
GPT OSS 20B is a reasoning model from OpenAI released on Jun 1, 2024. It reads text and writes text, with a 128K token context window and up to 16K tokens per reply.
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It costs $0.07 per million input tokens and $0.30 per million output tokens. Cached input bills at $0.035, 50% less than fresh input.
It supports tool calling, structured JSON output and prompt caching, and its weights are open, so you can host it yourself.
35 providers serve it, including Deep Infra, Vercel AI Gateway and SiliconFlow. The lowest input price is $0.018 per million tokens at Kilo Gateway.
On the Artificial Analysis Intelligence Index it scores 10, which places it at number 39 among the 43 models I track with independent scores.
- Modalities
- In / out price
- $0.07 / $0.30 per 1M
- Context
- 128K
- Max output
- 16K
- Released
- Jun 1, 2024
- Knowledge cutoff
- n/a
- Tool calling
- Structured output
- Reasoning
- Prompt caching
- Open weights
- Free to use
GPT OSS 20B pricing
USD, as listed on Oct 15, 2026. Most bills are input heavy, so the cached input rate matters as much as the headline price.
| Input | $0.07 / 1M tokens | |
|---|---|---|
| Output | $0.30 / 1M tokens | |
| Cached input (read) | $0.035 / 1M tokens | 50% off input |
GPT OSS 20B providers
35 providers serve it, including Deep Infra, Vercel AI Gateway and SiliconFlow. The lowest input price is $0.018 per million tokens at Kilo Gateway. Each host sets its own price and limits, so the cheapest one is not always the one with the longest context.
| Provider | Input /M | Output /M | Cache read /M | Context | Max output |
|---|---|---|---|---|---|
| Deep Infra | $0.03 | $0.14 | – | 131K | 16K |
| Vercel AI Gateway | $0.03 | $0.14 | – | 131K | 8K |
| SiliconFlow | $0.04 | $0.18 | – | 131K | 8K |
| OVHcloud AI Endpoints | $0.05 | $0.18 | – | 131K | 131K |
| Amazon Bedrock | $0.07 | $0.30 | – | 131K | 128K |
| OCI Generative AI | $0.07 | $0.30 | – | 128K | 16K |
| Groq | $0.075 | $0.30 | $0.0375 | 131K | 66K |
| Hugging Face | $0.10 | $0.50 | – | 131K | 33K |
| Cloudflare Workers AI | $0.20 | $0.30 | – | 128K | 16K |
| Kilo Gateway | $0.018 | $0.09 | $0.009 | 131K | 33K |
| CoreWeave | $0.03 | $0.13 | $0.03 | 131K | 131K |
| Eden AI | $0.03 | $0.14 | – | 131K | 33K |
Showing 12 of 35 providers: the lab first, then the major clouds, then the cheapest resellers.
What GPT OSS 20B costs per month
Pick a workload close to yours or type your own volumes.
Independent benchmarks
Measured by third parties, not reported by OpenAI. Each links to its source and shows the date I checked it.
A composite of 10 independent evaluations (agents 30%, coding 20%, scientific reasoning 20%, general 30%), run by Artificial Analysis on each model, version 4.3.2.
Artificial Analysis, checked Oct 10, 2026
Human preference: people compare two anonymous answers and pick the better one. Ratings from the Text Arena overall board, style control on.
Arena (formerly LMArena), checked Oct 10, 2026
Median output tokens per second measured by Artificial Analysis on the provider API, for the same model setting as its index score.
Artificial Analysis, checked Oct 10, 2026
Benchmarks OpenAI reports (8)
- gpqa-diamond (GPQA Diamond (without tools), high reasoning setting)71.5%
- hle-no-tools (Humanity's Last Exam (without tools), high reasoning setting)10.9%
- hle-with-tools (Humanity's Last Exam (with tools), high reasoning setting)17.3%
- aime-2025 (AIME 2025 (tools), high reasoning setting)98.7%
- mmlu (MMLU, high reasoning setting)85.3%
- codeforces (Codeforces Elo (with tools), high reasoning setting)2516
- tau-bench-retail (Tau-Bench Retail (function calling), high reasoning setting)54.8%
- healthbench (HealthBench, high reasoning setting)42.5%
Labs pick their own settings and harnesses, so compare these only within one lab.
Supported request parameters
What you can set when you call GPT OSS 20B through an OpenAI compatible API.
- Tools
tools - Structured outputs
structured_outputs - Reasoning
reasoning - Temperature
temperature
Alternatives to GPT OSS 20B
Models that take the same inputs and call tools, closest in price, cheaper ones first.
- 256K context
Reads text and images. Tool calling, structured output, reasoning. Served by 2 providers.
by bytedanceJul 26, 2025$0.07/M input tokens$0.30/M output tokens2 providers
- 1.05M context
Reads text, images, files, audio and video. Tool calling, structured output, reasoning. Served by 4 providers.
by metaSep 2, 2026$0.10/M input tokens$0.20/M output tokens4 providers
- 128K context
Reads text. Tool calling, structured output, reasoning. Served by 2 providers.
by liquidAug 11, 2026$0.10/M input tokens$0.20/M output tokens2 providers
Reads text, images, files, audio and video. Tool calling, structured output, reasoning. Served by 4 providers.
by metaAug 5, 2026$0.10/M input tokens$0.20/M output tokens4 providers
- 1.05M context
Reads text. Tool calling, reasoning. Served by 6 providers.
by poolsideJul 21, 2026$0.10/M input tokens$0.20/M output tokens6 providers
- 262K context
Reads text. Tool calling, reasoning. Served by 4 providers.
by poolsideJul 2, 2026$0.10/M input tokens$0.20/M output tokens4 providers
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by openaiSep 22, 2026$0.10/M input tokens$0.50/M output tokens2 providers
- 1.05M context
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by openaiSep 22, 2026$2/M input tokens$10/M output tokens27 providers
- 1.05M context
Reads text, images and files. Tool calling, structured output, reasoning. Served by 2 providers.
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GPT OSS 20B questions
How much does the GPT OSS 20B API cost?
$0.07 per million input tokens and $0.30 per million output tokens, with cached input at $0.035. The estimator on this page turns that into a monthly bill for your own workload.
What is the context window of GPT OSS 20B?
128,000 tokens of input, and it can write up to 16,384 tokens in one reply. As a rough guide, a million tokens is around 750,000 English words.
Which providers serve GPT OSS 20B?
35 providers serve it, including Deep Infra, Vercel AI Gateway and SiliconFlow. The lowest input price is $0.018 per million tokens at Kilo Gateway. Prices differ by host, so the Providers table on this page lists each one with its input and output price.
Does GPT OSS 20B support tool calling?
Yes. It accepts tool definitions and can return JSON that matches a schema, which is what an agent needs to call your APIs.
Is GPT OSS 20B open source?
Its weights are published, so you can run it on your own hardware or a cloud of your choice. Read the license before commercial use.
When was GPT OSS 20B released?
Jun 1, 2024.
How good is GPT OSS 20B compared with other models?
It scores 10 on the Artificial Analysis Intelligence Index and 1317 on the Arena text leaderboard. Benchmarks are a shortlist, not a verdict: test the top two or three candidates on your own tasks before you commit.
Catalog data from models.dev (MIT licensed), refreshed daily, last on Oct 15, 2026. Independent scores from my hand checked rankings, sources linked above. The summary is written from these facts.
Building on GPT OSS 20B?
I test your real tasks on it and the two closest alternatives, then ship the agent on whichever wins on cost and accuracy.
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