benchlm.ai

DeepSeek V3.1 vs GPT-5.3 Codex

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

Quick Verdict

GPT-5.3 Codex wins overall with a score of 85 vs 24 (61 point difference).GPT-5.3 Codex wins 4 out of 4 categories.

DeepSeek V3.1

CreatorDeepSeek
TypeOpen Weight
Context128K
Score24

GPT-5.3 Codex

CreatorOpenAI
TypeProprietary
Context400K
Score85

Knowledge

GPT-5.3 Codex

DeepSeek V3.1

30.8

GPT-5.3 Codex

96

33
MMLU
99
32
GPQA
97
30
SuperGPQA
95
28
OpenBookQA
93

Coding

GPT-5.3 Codex

DeepSeek V3.1

25

GPT-5.3 Codex

95

25
HumanEval
95

Mathematics

GPT-5.3 Codex

DeepSeek V3.1

32

GPT-5.3 Codex

97.1

33
AIME 2023
99
35
AIME 2024
99
34
AIME 2025
98
29
HMMT Feb 2023
95
31
HMMT Feb 2024
97
30
HMMT Feb 2025
96
32
BRUMO 2025
96

Reasoning

GPT-5.3 Codex

DeepSeek V3.1

30

GPT-5.3 Codex

94

31
SimpleQA
95
29
MuSR
93

Frequently Asked Questions

Which is better, DeepSeek V3.1 or GPT-5.3 Codex?

GPT-5.3 Codex scores higher overall with 85 vs 24, a difference of 61 points across all benchmarks.

Which is better for knowledge tasks, DeepSeek V3.1 or GPT-5.3 Codex?

GPT-5.3 Codex leads in knowledge tasks with an average score of 96 vs 30.8.

Which is better for coding, DeepSeek V3.1 or GPT-5.3 Codex?

GPT-5.3 Codex leads in coding with an average score of 95 vs 25.

Which is better for math, DeepSeek V3.1 or GPT-5.3 Codex?

GPT-5.3 Codex leads in math with an average score of 97.1 vs 32.

Which is better for reasoning, DeepSeek V3.1 or GPT-5.3 Codex?

GPT-5.3 Codex leads in reasoning with an average score of 94 vs 30.

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DeepSeek V3.1 vs GPT-5.4DeepSeek V3.1 vs Gemini 3.1 ProDeepSeek V3.1 vs Claude Opus 4.6DeepSeek V3.1 vs Grok 4.1DeepSeek V3.1 vs GPT-5.2DeepSeek V3.1 vs GPT-5.2-Codex