GPT-5.3-Codex-Spark vs GPT-4o

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 56. 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 32.2. The single biggest benchmark swing on the page is SWE-bench Verified, 80 to 20.

GPT-4o is also the more expensive model on tokens at $2.50 input / $10.00 output per 1M tokens, versus $2.00 input / $8.00 output per 1M tokens for GPT-5.3-Codex-Spark. GPT-5.3-Codex-Spark is the reasoning model in the pair, while GPT-4o 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 GPT-4o.

Quick Verdict

Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. GPT-4o 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

GPT-4o

51.2

90
Terminal-Bench 2.0
49
82
BrowseComp
59
83
OSWorld-Verified
48

Coding

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

82.3

GPT-4o

32.2

91
HumanEval
58
80
SWE-bench Verified
20
80
LiveCodeBench
38
85
SWE-bench Pro
29

Multimodal & Grounded

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

88.3

GPT-4o

72.2

86
MMMU-Pro
74
91
OfficeQA Pro
70

Reasoning

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92.7

GPT-4o

64.6

94
SimpleQA
64
92
MuSR
62
97
BBH
82
91
LongBench v2
62
92
MRCRv2
63

Knowledge

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

78.3

GPT-4o

47.4

97
MMLU
66
95
GPQA
66
93
SuperGPQA
64
91
OpenBookQA
62
88
MMLU-Pro
64
42
HLE
1
88
FrontierScience
58

Instruction Following

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92

GPT-4o

82

92
IFEval
82

Multilingual

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

90.8

GPT-4o

75.5

94
MGSM
82
89
MMLU-ProX
72

Mathematics

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

96.7

GPT-4o

71.8

98
AIME 2023
66
98
AIME 2024
68
97
AIME 2025
67
94
HMMT Feb 2023
62
96
HMMT Feb 2024
64
95
HMMT Feb 2025
63
95
BRUMO 2025
65
98
MATH-500
80

Frequently Asked Questions

Which is better, GPT-5.3-Codex-Spark or GPT-4o?

GPT-5.3-Codex-Spark is ahead overall, 87 to 56. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 80 and 20.

Which is better for knowledge tasks, GPT-5.3-Codex-Spark or GPT-4o?

GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 47.4. 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 GPT-4o?

GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 32.2. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.3-Codex-Spark or GPT-4o?

GPT-5.3-Codex-Spark has the edge for math in this comparison, averaging 96.7 versus 71.8. 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 GPT-4o?

GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 64.6. 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 GPT-4o?

GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 51.2. 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 GPT-4o?

GPT-5.3-Codex-Spark has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 72.2. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.3-Codex-Spark or GPT-4o?

GPT-5.3-Codex-Spark has the edge for instruction following in this comparison, averaging 92 versus 82. 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 GPT-4o?

GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 75.5. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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