GPT-5.3-Codex-Spark vs o4-mini (high)

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 63. 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 38.7. The single biggest benchmark swing on the page is LiveCodeBench, 80 to 34.

GPT-5.3-Codex-Spark is the reasoning model in the pair, while o4-mini (high) 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 200K for o4-mini (high).

Quick Verdict

Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. o4-mini (high) 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

o4-mini (high)

58.5

90
Terminal-Bench 2.0
58
82
BrowseComp
64
83
OSWorld-Verified
55

Coding

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

82.3

o4-mini (high)

38.7

91
HumanEval
74
80
SWE-bench Verified
45
80
LiveCodeBench
34
85
SWE-bench Pro
42

Multimodal & Grounded

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

88.3

o4-mini (high)

68.3

86
MMMU-Pro
66
91
OfficeQA Pro
71

Reasoning

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92.7

o4-mini (high)

77.4

94
SimpleQA
80
92
MuSR
78
97
BBH
83
91
LongBench v2
75
92
MRCRv2
74

Knowledge

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

78.3

o4-mini (high)

61.2

97
MMLU
82
95
GPQA
82
93
SuperGPQA
80
91
OpenBookQA
78
88
MMLU-Pro
76
42
HLE
13
88
FrontierScience
73

Instruction Following

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92

o4-mini (high)

83

92
IFEval
83

Multilingual

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

90.8

o4-mini (high)

81.7

94
MGSM
83
89
MMLU-ProX
81

Mathematics

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

96.7

o4-mini (high)

82.9

98
AIME 2023
83
98
AIME 2024
85
97
AIME 2025
84
94
HMMT Feb 2023
79
96
HMMT Feb 2024
81
95
HMMT Feb 2025
80
95
BRUMO 2025
82
98
MATH-500
84

Frequently Asked Questions

Which is better, GPT-5.3-Codex-Spark or o4-mini (high)?

GPT-5.3-Codex-Spark is ahead overall, 87 to 63. The biggest single separator in this matchup is LiveCodeBench, where the scores are 80 and 34.

Which is better for knowledge tasks, GPT-5.3-Codex-Spark or o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 61.2. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.3-Codex-Spark or o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 38.7. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.3-Codex-Spark or o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for math in this comparison, averaging 96.7 versus 82.9. 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 o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 77.4. Inside this category, MRCRv2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.3-Codex-Spark or o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 58.5. 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 o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 68.3. 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 o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for instruction following in this comparison, averaging 92 versus 83. 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 o4-mini (high)?

GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 81.7. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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