OpenAI: gpt-oss-20b (free)
The OpenAI gpt-oss-20b is a powerful text-based AI model with a context length of 131,072 tokens and supports reasoning and tool integration for enhanced functionality. Its performance shines in tasks requiring extensive understanding, making it suitable for complex queries and problem-solving scenarios. Given its free pricing and robust benchmark scores-particularly strong in coding and agentic behavior-it stands out as an excellent choice for users seeking a versatile AI solution without budget constraints. With a blended benchmark score of 25.7 across four independent assessments, this model offers reliable performance across various applications.
Benchmark results
Independent, published benchmarks. Blended score 25.6 across 4 benchmarks, last refreshed 2026-07-27. How scoring works →
| Benchmark | Measures | Score |
|---|---|---|
| AI Index | broad capability composite | 24.6 |
| AI Index Coding | software engineering tasks | 34.1 |
| AI Index Agentic | multi-step tool-using tasks | 5.1 |
| EQ-Bench | emotional understanding in dialogue | 40.7 |
- Model ID
- openai/gpt-oss-20b:free
- Vendor
- openai
- Released
- August 2025
- Tokenizer
- GPT
- Input Modalities
- text
- Output Modalities
- text
- Max Output
- 32,768 tokens
- Tool Calling
- ✓ supported
- Structured Output
- ✓ supported
- Reasoning Mode
- ✓ supported
- Vision
- text only
- Audio
- no
- Moderated
- no
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Quick answers
- Is OpenAI: gpt-oss-20b (free) free to use?
- Yes. It is currently listed at no cost per token via OpenRouter, subject to provider rate limits.
- What is OpenAI: gpt-oss-20b (free)'s context window?
- 131,072 tokens, roughly 196 pages of text in a single request.
- Does OpenAI: gpt-oss-20b (free) support tool calling?
- It supports tool calling, structured output, a reasoning mode.
- Can OpenAI: gpt-oss-20b (free) process images?
- No, it is text-only on the input side.