gpt-oss-20b
gpt-oss-20bgpt-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... Built by OpenAI.
Prices updated
Input price
$0.02
per 1M tokens · Standard
Output price
$0.09
per 1M tokens · Standard
Input limit
131K
tokens
Output limit
33K
tokens
Input formats
Output formats
gpt-oss-20b price history
2 price records since 9/25/2026
gpt-oss-20b cost calculator
$0.81/month
Standard pricing
Overview
What is gpt-oss-20b?
gpt-oss-20b is a text & reasoning model from OpenAI. 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... Its 131K context window and $0.02 input price make it a candidate for cost-sensitive, high-throughput applications.
Benchmarks
gpt-oss-20b benchmarks & speed
How gpt-oss-20b scores on standardized evaluations, and where it lands among every model we track.
9.0
Intelligence Index
207tok/s
Output speed
Reasoning
GPQA Diamond
68.8%
Graduate-level scientific reasoning · top 70%
HLE
11.0%
Humanity's Last Exam · top 64%
Coding
SciCode
38.9%
Python for scientific computing · top 83%
Latency & design
- Time to first token
- 0.85s
Independent scores from Artificial Analysis and DesignArena · updated 10/5/2026. Higher is better; ranks compare against every model we track with that score.
Rates
gpt-oss-20b pricing
Pricing is based on token usage. Provider-specific caching, batch, regional, and tool charges may affect the final cost.
Input · Standard
$0.02
Per 1M tokens
Cached input · Standard
$0.0090
Per 1M tokens
Capabilities
gpt-oss-20b Tools
Tools available when using gpt-oss-20b through supported provider APIs.
Function calling
Supported
Structured outputs
Supported
JSON mode
Supported
Reasoning
Supported
Built-in web search
Not supported
Log probabilities
Supported
Deterministic seed
Supported
Parallel tool calls
Not supported
Prompt caching
Supported
Strengths and limitations
Strengths
- Low input cost at $0.02 per million tokens suits high-volume workloads.
- A 131K context window covers most focused application workflows.
- Supports text & reasoning workloads in one model.
Limitations
- Generated tokens cost 5× more than input tokens, which matters for verbose responses.
- The 131K context window is smaller than several long-context alternatives.
- Arena Elo and MMLU-Pro are directional; test accuracy, latency and reliability on your own workload before committing.
Arena Elo, MMLU-Pro and pricing figures are illustrative; validate current vendor terms before purchase.
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