OpenAI · Released Aug 5, 2025
gpt-oss-20b
gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...
- Released
- Aug 5 2025
- Context window
- 131K 33K out
- Input / 1M tokens
- $0.018
- Output / 1M tokens
- $0.09
Where to run it
10 providers compared
Cheapest: Darkbloom at $0.018 / $0.09 per 1M input / output tokens — 73% less than the priciest option.
| Provider | Input | Output | Cache read | Context | Max output | Uptime | vs. best |
|---|---|---|---|---|---|---|---|
| DarkbloomFP8 | $0.018 | $0.09 | $0.009 | 131K | 33K | 100%24h | Cheapest |
| AkashMLFP4 | $0.02 | $0.10 | — | 131K | 118K | 99.9%24h | +11% |
| CoreWeaveFP4 | $0.03 | $0.13 | $0.03 | 131K | 118K | 100%24h | +53% |
| DekaLLMBF16 | $0.029 | $0.14 | $0.029 | 131K | 118K | 100%24h | +58% |
| DeepInfraBF16 | $0.03 | $0.14 | — | 131K | 118K | 99.6%24h | +60% |
| ParasailFP4 | $0.03 | $0.15 | $0.02 | 131K | 118K | 97.8%24h | +67% |
| SiliconFlowFP8 · no tool calling | $0.04 | $0.18 | — | 131K | 8K | 92.1%24h | +108% |
| Amazon Bedrockeu-west-1 | $0.07 | $0.15 | — | 131K | 118K | 100%24h | +150% |
| Amazon Bedrock | $0.07 | $0.15 | — | 131K | 118K | 100%24h | +150% |
| Googleus-central1 · no tool calling | $0.07 | $0.25 | — | 131K | 33K | 98.8%24h | +219% |
| Groq | $0.075 | $0.30 | $0.038 | 131K | 66K | 99.8%24h | +265% |
Value
Price vs. performance
gpt-oss-20b Other OpenAI Other labs Value frontier · GPQA Diamond vs. input price per 1M tokens (log scale) · Drag to pan, pinch or Ctrl + scroll to zoom, double-click to zoom in.
Benchmarks
6 benchmark scores
| Benchmark | Score | Rank | Leader |
|---|---|---|---|
| Terminal-BenchSoftware engineering · Tasks completed with the programs in a real terminal (best agent) | 3.4% | #40of 40 | GPT-5.584.7% |
| SciCodeSoftware engineering · Research-coding problems from the natural sciences | 38.9% | #77of 93 | Claude Opus 5.566.9% |
| GPQA DiamondReasoning & knowledge · PhD-level biology, chemistry and physics questions | 60.8% | #86of 92 | Gemini 4 Argon96.4% |
| CritPtReasoning & knowledge · Open-ended, research-level physics problems | 1.4% | #73of 96 | GPT-5.6 Sol32.3% |
| LMCAReasoning & knowledge · Judge the quality of conceptual arguments like experts | 14.5% | #94of 96 | Claude Sonnet 5.568.3% |
| OTIS Mock AIMEMaths · Competition-style problems harder than MATH Level 5 | 65.3% | #84of 90 | Gemini 4 Argon100.0% |
Specs
Details
- Model ID
openai/gpt-oss-20b- Developer
- OpenAI
- Release date
- Aug 5, 2025 ·
- Context window
- 131,072 tokens
- Max output
- 32,768 tokens
- API price
- $0.018 / $0.09 per 1M input / output tokens
- Providers
- 10
- Input types
- text
- Reasoning
- Yes
- Tool calling
- Yes
- Open weights
- Yes
- Free tier
- No
Release date, prices and providers from OpenRouter's catalog; buying directly from a provider can cost a little differently. Uptime is the share of OpenRouter requests each provider served over the last day. Benchmark scores are the best result per benchmark from Epoch AI, licensed CC BY 4.0. Rank counts every model tracked here with a score.