GPT-5.3-Codex-Spark vs o1-preview

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 77. 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 64.6. The single biggest benchmark swing on the page is LiveCodeBench, 80 to 60.

GPT-5.3-Codex-Spark gives you the larger context window at 256K, compared with 200K for o1-preview.

Quick Verdict

Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. o1-preview only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.

Agentic

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

85.6

o1-preview

75.4

90
Terminal-Bench 2.0
77
82
BrowseComp
79
83
OSWorld-Verified
71

Coding

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

82.3

o1-preview

64.6

91
HumanEval
86
80
SWE-bench Verified
65
80
LiveCodeBench
60
85
SWE-bench Pro
69

Multimodal & Grounded

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

88.3

o1-preview

75.6

86
MMMU-Pro
72
91
OfficeQA Pro
80

Reasoning

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92.7

o1-preview

86.8

94
SimpleQA
88
92
MuSR
86
97
BBH
93
91
LongBench v2
87
92
MRCRv2
83

Knowledge

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

78.3

o1-preview

71.3

97
MMLU
92
95
GPQA
90
93
SuperGPQA
88
91
OpenBookQA
86
88
MMLU-Pro
80
42
HLE
32
88
FrontierScience
83

Instruction Following

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92

o1-preview

88

92
IFEval
88

Multilingual

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

90.8

o1-preview

87.4

94
MGSM
90
89
MMLU-ProX
86

Mathematics

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

96.7

o1-preview

93.5

98
AIME 2023
94
98
AIME 2024
96
97
AIME 2025
95
94
HMMT Feb 2023
90
96
HMMT Feb 2024
92
95
HMMT Feb 2025
91
95
BRUMO 2025
93
98
MATH-500
94

Frequently Asked Questions

Which is better, GPT-5.3-Codex-Spark or o1-preview?

GPT-5.3-Codex-Spark is ahead overall, 87 to 77. The biggest single separator in this matchup is LiveCodeBench, where the scores are 80 and 60.

Which is better for knowledge tasks, GPT-5.3-Codex-Spark or o1-preview?

GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 71.3. 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 o1-preview?

GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 64.6. 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 o1-preview?

GPT-5.3-Codex-Spark has the edge for math in this comparison, averaging 96.7 versus 93.5. 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 o1-preview?

GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 86.8. 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 o1-preview?

GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 75.4. 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 o1-preview?

GPT-5.3-Codex-Spark has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 75.6. 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 o1-preview?

GPT-5.3-Codex-Spark has the edge for instruction following in this comparison, averaging 92 versus 88. 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 o1-preview?

GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 87.4. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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