DeepSeek V3 vs GPT-5.1-Codex-Max

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

GPT-5.1-Codex-Max is clearly ahead on the aggregate, 62 to 25. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.1-Codex-Max's sharpest advantage is in reasoning, where it averages 92.9 against 24.9. The single biggest benchmark swing on the page is SimpleQA, 24.9% to 94%.

GPT-5.1-Codex-Max is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.27 input / $1.10 output per 1M tokens for DeepSeek V3. That is roughly 7.3x on output cost alone. GPT-5.1-Codex-Max is the reasoning model in the pair, while DeepSeek V3 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-5.1-Codex-Max gives you the larger context window at 400K, compared with 128K for DeepSeek V3.

Quick Verdict

Pick GPT-5.1-Codex-Max if you want the stronger benchmark profile. DeepSeek V3 only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

Coming soon
Terminal-Bench 2.0
58.1%

Coding

GPT-5.1-Codex-Max

DeepSeek V3

42

GPT-5.1-Codex-Max

86

42%
SWE-bench Verified
77.9%
Coming soon
HumanEval
94%

Multimodal & Grounded

Coming soon

Benchmark data for this category is coming soon.

Reasoning

GPT-5.1-Codex-Max

DeepSeek V3

24.9

GPT-5.1-Codex-Max

92.9

24.9%
SimpleQA
94%
Coming soon
MuSR
92%

Knowledge

GPT-5.1-Codex-Max

DeepSeek V3

69.6

GPT-5.1-Codex-Max

95

59.1%
GPQA
96%
88.5%
MMLU
98%
75.9%
MMLU-Pro
Coming soon
Coming soon
SuperGPQA
94%
Coming soon
OpenBookQA
92%

Instruction Following

Coming soon

Benchmark data for this category is coming soon.

Multilingual

Coming soon

Benchmark data for this category is coming soon.

Mathematics

GPT-5.1-Codex-Max

DeepSeek V3

90.2

GPT-5.1-Codex-Max

96

39.2%
AIME 2024
99%
90.2%
MATH-500
Coming soon
Coming soon
AIME 2023
99%
Coming soon
AIME 2025
98%
Coming soon
HMMT Feb 2023
95%
Coming soon
HMMT Feb 2024
97%
Coming soon
HMMT Feb 2025
96%
Coming soon
BRUMO 2025
96%

Frequently Asked Questions

Which is better, DeepSeek V3 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max is ahead overall, 62 to 25. The biggest single separator in this matchup is SimpleQA, where the scores are 24.9% and 94%.

Which is better for knowledge tasks, DeepSeek V3 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max has the edge for knowledge tasks in this comparison, averaging 95 versus 69.6. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, DeepSeek V3 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max has the edge for coding in this comparison, averaging 86 versus 42. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, DeepSeek V3 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max has the edge for math in this comparison, averaging 96 versus 90.2. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for reasoning, DeepSeek V3 or GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max has the edge for reasoning in this comparison, averaging 92.9 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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