openai/gpt-oss-20bgpt-oss-20b is OpenAI’s open-weights AI model, released Aug 5, 2025. It costs $0.03/M input and $0.14/M output tokens, and handles a 131K-token context window.
gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license.
Scores on standardized evaluations. Higher is better — and rank shows where gpt-oss-20b lands among all models tracked on Model Beat.
Graduate-level scientific reasoning
Frontier of human expert knowledge
Broad expert knowledge
Novel ML problem-solving
Contamination-free coding
Scientific research coding
Olympiad-qualifier math
Command-line agentic tasks
Tool-agent-user reliability
gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license.
gpt-oss-20b is an AI model developed by OpenAI, part of the GPT family, released Aug 5, 2025.
gpt-oss-20b is served from $0.03 per million input tokens and $0.14 per million output tokens (cheapest credible provider on OpenRouter: DeepInfra).
gpt-oss-20b supports a context window of up to 131K tokens.
On standardized evaluations tracked by Epoch AI, gpt-oss-20b scores 89.3% on AIME 2024/2025, 77.7% on LiveCodeBench, 60.2% on τ²-bench.
gpt-oss-20b is released with open weights (Open weights (unrestricted)), so the model can be downloaded and self-hosted.
Benchmark data from Epoch AI (CC BY) and Artificial Analysis; pricing, specs & descriptions from OpenRouter. Data updated Jul 30, 2026.