OpenAI: gpt-oss-20b (free)
Analysis Summary
OpenAI's gpt-oss-20b (free) is a no-cost, compact model with a 131K context window, tool use, and function calling. Its intelligence index of 24.5 and a strong math score of 89.3 make it capable for its size, though the coding index of 18.5 is below average and no agentic index is reported.
For businesses, the free tier makes it attractive for high-volume, low-stakes tasks such as classification, summarisation, and structured data extraction. The limited coding capability means it is not suitable for software engineering workflows, and the absence of vision restricts multimodal use.
As a zero-cost option from a trusted provider with tool use included, it is a strong choice for teams needing to process large volumes of text cheaply. Pair it with a stronger model for tasks requiring deep reasoning or code generation.
Assessed June 6, 2026
Editorial notes
GPT-OSS-20B (free) from OpenAI delivers solid reasoning and math performance at no cost, with tool use and function calling, though coding capability is limited and no agentic index is available.
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
Performance Profile
How OpenAI: gpt-oss-20b (free) compares
OpenAI: gpt-oss-20b (free) ranks #106 of 380 AI models we track for overall intelligence, #154 of 317 for coding. Its 131K-token context window is larger than 59% of the models we list. OpenAI: gpt-oss-20b (free) is currently free to use via OpenRouter.
About OpenAI: gpt-oss-20b (free)
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..
Capabilities
Performance Indices
Source: Artificial Analysis
Benchmark Scores
Intelligence
Technical
Benchmark data from Artificial Analysis and Hugging Face
How does OpenAI: gpt-oss-20b (free) stack up?
Compare side-by-side with other professional models.
Model Information
| OpenRouter ID |
openai/gpt-oss-20b:free
|
| Provider | openai |
| Release Date | August 5, 2025 |
| Context Length | 131,072 tokens |
| Max Completion | 8,192 tokens |
| Status | Active |
Live Performance
Live endpoint metrics, refreshed every 30 minutes.
Leaderboard Categories
External Resources
Frequently asked questions about OpenAI: gpt-oss-20b (free)
How much does OpenAI: gpt-oss-20b (free) cost?
OpenAI: gpt-oss-20b (free) is currently available for free via OpenRouter.
What is the context window of OpenAI: gpt-oss-20b (free)?
OpenAI: gpt-oss-20b (free) has a context window of 131,072 tokens (131K).
Is OpenAI: gpt-oss-20b (free) good for coding?
On our coding benchmark index, OpenAI: gpt-oss-20b (free) ranks #154 of 317 models, placing it in the broader range of the field for code generation and debugging.
What can OpenAI: gpt-oss-20b (free) do?
OpenAI: gpt-oss-20b (free) supports tool use and function calling.
Who created OpenAI: gpt-oss-20b (free)?
OpenAI: gpt-oss-20b (free) is developed by OpenAI and was released on August 5, 2025.
