GPT-5.3-Codex-Spark vs DeepSeek V3.1

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

GPT-5.3-Codex-Spark is clearly ahead on the aggregate, 87 to 35. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.3-Codex-Spark's sharpest advantage is in coding, where it averages 82.3 against 14.8. The single biggest benchmark swing on the page is SWE-bench Pro, 85 to 15.

GPT-5.3-Codex-Spark is the reasoning model in the pair, while DeepSeek V3.1 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-5.3-Codex-Spark gives you the larger context window at 256K, compared with 128K for DeepSeek V3.1.

Quick Verdict

Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. DeepSeek V3.1 only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

85.6

DeepSeek V3.1

32.9

90
Terminal-Bench 2.0
29
82
BrowseComp
39
83
OSWorld-Verified
33

Coding

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

82.3

DeepSeek V3.1

14.8

91
HumanEval
25
80
SWE-bench Verified
13
80
LiveCodeBench
15
85
SWE-bench Pro
15

Multimodal & Grounded

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

88.3

DeepSeek V3.1

39.5

86
MMMU-Pro
35
91
OfficeQA Pro
45

Reasoning

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92.7

DeepSeek V3.1

40.7

94
SimpleQA
31
92
MuSR
29
97
BBH
61
91
LongBench v2
46
92
MRCRv2
48

Knowledge

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

78.3

DeepSeek V3.1

30.5

97
MMLU
33
95
GPQA
32
93
SuperGPQA
30
91
OpenBookQA
28
88
MMLU-Pro
53
42
HLE
2
88
FrontierScience
37

Instruction Following

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92

DeepSeek V3.1

67

92
IFEval
67

Multilingual

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

90.8

DeepSeek V3.1

60.8

94
MGSM
64
89
MMLU-ProX
59

Mathematics

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

96.7

DeepSeek V3.1

44.2

98
AIME 2023
33
98
AIME 2024
35
97
AIME 2025
34
94
HMMT Feb 2023
29
96
HMMT Feb 2024
31
95
HMMT Feb 2025
30
95
BRUMO 2025
32
98
MATH-500
59

Frequently Asked Questions

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

GPT-5.3-Codex-Spark is ahead overall, 87 to 35. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 85 and 15.

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

GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 30.5. Inside this category, MMLU is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 14.8. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for math in this comparison, averaging 96.7 versus 44.2. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 40.7. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 32.9. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.3-Codex-Spark or DeepSeek V3.1?

GPT-5.3-Codex-Spark has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 39.5. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.3-Codex-Spark or DeepSeek V3.1?

GPT-5.3-Codex-Spark has the edge for instruction following in this comparison, averaging 92 versus 67. Inside this category, IFEval is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 60.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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