GPT-OSS 20B Benchmark Scores & Performance

Benchmark analysis of GPT-OSS 20B by OpenAI across 14 tests.

Creator

OpenAI

Source Type

Open Weight

Reasoning

Non-Reasoning

Context Window

128K

Overall Score

22#86 of 88

Knowledge Benchmarks

MMLU
31
GPQA
30
SuperGPQA
28
OpenBookQA
26

Coding Benchmarks

HumanEval
23

Mathematics Benchmarks

AIME 2023
31
AIME 2024
33
AIME 2025
32
HMMT Feb 2023
27
HMMT Feb 2024
29
HMMT Feb 2025
28
BRUMO 2025
30

Reasoning Benchmarks

SimpleQA
29
MuSR
27

Frequently Asked Questions

How does GPT-OSS 20B perform overall in AI benchmarks?

GPT-OSS 20B ranks #86 out of 88 models with an overall score of 22. It is created by OpenAI and features a 128K context window.

Is GPT-OSS 20B good for knowledge and understanding?

GPT-OSS 20B ranks #86 out of 88 models in knowledge and understanding benchmarks with an average score of 28.8. There are stronger options in this category.

Is GPT-OSS 20B good for coding and programming?

GPT-OSS 20B ranks #86 out of 88 models in coding and programming benchmarks with an average score of 23. There are stronger options in this category.

Is GPT-OSS 20B good for mathematics?

GPT-OSS 20B ranks #86 out of 88 models in mathematics benchmarks with an average score of 30. There are stronger options in this category.

Is GPT-OSS 20B good for reasoning and logic?

GPT-OSS 20B ranks #86 out of 88 models in reasoning and logic benchmarks with an average score of 28. There are stronger options in this category.

Is GPT-OSS 20B open source?

Yes, GPT-OSS 20B is an open weight model created by OpenAI, meaning it can be downloaded and run locally or fine-tuned for specific use cases.

What is the context window size of GPT-OSS 20B?

GPT-OSS 20B has a context window of 128K tokens, which determines how much text it can process in a single interaction.