GPT-5.3-Codex-Spark vs GPT-5 (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 79. 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 66.1. The single biggest benchmark swing on the page is LiveCodeBench, 80 to 62. GPT-5 (high) does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.

GPT-5.3-Codex-Spark gives you the larger context window at 256K, compared with 128K for GPT-5 (high).

Quick Verdict

Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. GPT-5 (high) only becomes the better choice if multimodal & grounded is the priority.

Agentic

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

85.6

GPT-5 (high)

75.2

90
Terminal-Bench 2.0
78
82
BrowseComp
75
83
OSWorld-Verified
72

Coding

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

82.3

GPT-5 (high)

66.1

91
HumanEval
85
80
SWE-bench Verified
67
80
LiveCodeBench
62
85
SWE-bench Pro
70

Multimodal & Grounded

GPT-5 (high)

GPT-5.3-Codex-Spark

88.3

GPT-5 (high)

89.4

86
MMMU-Pro
93
91
OfficeQA Pro
85

Reasoning

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92.7

GPT-5 (high)

85.7

94
SimpleQA
89
92
MuSR
87
97
BBH
94
91
LongBench v2
83
92
MRCRv2
80

Knowledge

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

78.3

GPT-5 (high)

71.1

97
MMLU
93
95
GPQA
91
93
SuperGPQA
89
91
OpenBookQA
87
88
MMLU-Pro
83
42
HLE
27
88
FrontierScience
83

Instruction Following

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92

GPT-5 (high)

91

92
IFEval
91

Multilingual

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

90.8

GPT-5 (high)

86.4

94
MGSM
89
89
MMLU-ProX
85

Mathematics

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

96.7

GPT-5 (high)

94

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

Frequently Asked Questions

Which is better, GPT-5.3-Codex-Spark or GPT-5 (high)?

GPT-5.3-Codex-Spark is ahead overall, 87 to 79. The biggest single separator in this matchup is LiveCodeBench, where the scores are 80 and 62.

Which is better for knowledge tasks, GPT-5.3-Codex-Spark or GPT-5 (high)?

GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 71.1. 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-5 (high)?

GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 66.1. 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 GPT-5 (high)?

GPT-5.3-Codex-Spark has the edge for math in this comparison, averaging 96.7 versus 94. Inside this category, MATH-500 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.3-Codex-Spark or GPT-5 (high)?

GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 85.7. 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 GPT-5 (high)?

GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 75.2. 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-5 (high)?

GPT-5 (high) has the edge for multimodal and grounded tasks in this comparison, averaging 89.4 versus 88.3. 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 GPT-5 (high)?

GPT-5.3-Codex-Spark has the edge for instruction following in this comparison, averaging 92 versus 91. 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-5 (high)?

GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 86.4. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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