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gpt-oss-20b

by OpenAI · Released Aug 2025

Open Source
44.4
avg score
Rank #126
Compare
Better than 46% of all models
Context
131K tokens (~66 books)
Input $/1M
$0.03
Output $/1M
$0.14
Type
text
License
Open Source
Benchmarks
6 tested
Data updated today
About

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...

Tested on 6 benchmarks with 67.4% average. Top scores: Chatbot Arena Elo — Overall (1317.7%), HELM — MMLU-Pro (74.0%), HELM — WildBench (73.7%).

Capabilities
reasoning
73.7
#18 globally
math
56.5
#58 globally
knowledge
66.7
#26 globally
language
73.2
#64 globally
Benchmark Scores
Compare All
Tested on 6 benchmarks · Ranked across 5 categories
Score Distribution (all 233 models)
0255075100
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HELM — WildBench

Stanford HELM WildBench evaluation. Tests reasoning on challenging real-world tasks.

73.7
HELM — Omni-MATH

Stanford HELM evaluation of mathematical reasoning across diverse problem types.

56.5
HELM — MMLU-Pro

Stanford HELM evaluation of MMLU-Pro. Tests broad knowledge with increased difficulty.

74.0
HELM — GPQA

Stanford HELM evaluation of GPQA. Tests graduate-level scientific reasoning.

59.4
Excellent (85+) Good (70-85) Average (50-70) Below (<50)
Links
Documentation
Community
BenchGecko API
gpt-oss-20b
Specifications
  • Typetext
  • Context131K tokens (~66 books)
  • ReleasedAug 2025
  • LicenseOpen Source
  • StatusActive
  • Cost / Message~$0.000
Available On
OpenAI logoOpenAI$0.03
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gpt-oss-20b is an open-source text AI model by OpenAI, released in August 2025. It has an average benchmark score of 44.4. Context window: 131K tokens.