DeepSeek V3 vs GPT-OSS 20B

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

DeepSeek V3 is clearly ahead on the aggregate, 25 to 14. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

DeepSeek V3's sharpest advantage is in mathematics, where it averages 90.2 against 30. The single biggest benchmark swing on the page is MMLU, 88.5% to 31%. GPT-OSS 20B does hit back in reasoning, so the answer changes if that is the part of the workload you care about most.

Quick Verdict

Pick DeepSeek V3 if you want the stronger benchmark profile. GPT-OSS 20B only becomes the better choice if reasoning is the priority.

Agentic

Coming soon

Benchmark data for this category is coming soon.

Coding

DeepSeek V3

DeepSeek V3

42

GPT-OSS 20B

23

42%
SWE-bench Verified
Coming soon
Coming soon
HumanEval
23%

Multimodal & Grounded

Coming soon

Benchmark data for this category is coming soon.

Reasoning

GPT-OSS 20B

DeepSeek V3

24.9

GPT-OSS 20B

27.9

24.9%
SimpleQA
29%
Coming soon
MuSR
27%

Knowledge

DeepSeek V3

DeepSeek V3

69.6

GPT-OSS 20B

29

59.1%
GPQA
30%
88.5%
MMLU
31%
75.9%
MMLU-Pro
Coming soon
Coming soon
SuperGPQA
28%
Coming soon
OpenBookQA
26%

Instruction Following

Coming soon

Benchmark data for this category is coming soon.

Multilingual

Coming soon

Benchmark data for this category is coming soon.

Mathematics

DeepSeek V3

DeepSeek V3

90.2

GPT-OSS 20B

30

39.2%
AIME 2024
33%
90.2%
MATH-500
Coming soon
Coming soon
AIME 2023
31%
Coming soon
AIME 2025
32%
Coming soon
HMMT Feb 2023
27%
Coming soon
HMMT Feb 2024
29%
Coming soon
HMMT Feb 2025
28%
Coming soon
BRUMO 2025
30%

Frequently Asked Questions

Which is better, DeepSeek V3 or GPT-OSS 20B?

DeepSeek V3 is ahead overall, 25 to 14. The biggest single separator in this matchup is MMLU, where the scores are 88.5% and 31%.

Which is better for knowledge tasks, DeepSeek V3 or GPT-OSS 20B?

DeepSeek V3 has the edge for knowledge tasks in this comparison, averaging 69.6 versus 29. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, DeepSeek V3 or GPT-OSS 20B?

DeepSeek V3 has the edge for coding in this comparison, averaging 42 versus 23. GPT-OSS 20B stays close enough that the answer can still flip depending on your workload.

Which is better for math, DeepSeek V3 or GPT-OSS 20B?

DeepSeek V3 has the edge for math in this comparison, averaging 90.2 versus 30. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for reasoning, DeepSeek V3 or GPT-OSS 20B?

GPT-OSS 20B has the edge for reasoning in this comparison, averaging 27.9 versus 24.9. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Last updated: March 17, 2026

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