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

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 52. 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 reasoning, where it averages 92.7 against 49.4. The single biggest benchmark swing on the page is LongBench v2, 91 to 49.

GPT-5.3-Codex-Spark is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.15 input / $0.60 output per 1M tokens for GPT-4o mini. That is roughly 13.3x on output cost alone. GPT-5.3-Codex-Spark is the reasoning model in the pair, while GPT-4o mini 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 mini.

Quick Verdict

Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. GPT-4o mini only becomes the better choice if you want the cheaper token bill or 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 mini

50.9

90
Terminal-Bench 2.0
58
82
BrowseComp
49
83
OSWorld-Verified
44

Coding

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

82.3

GPT-4o mini

65

91
HumanEval
87.2
80
SWE-bench Verified
Coming soon
80
LiveCodeBench
Coming soon
85
SWE-bench Pro
65

Multimodal & Grounded

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

88.3

GPT-4o mini

60.2

86
MMMU-Pro
66
91
OfficeQA Pro
53

Reasoning

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

92.7

GPT-4o mini

49.4

94
SimpleQA
Coming soon
92
MuSR
Coming soon
97
BBH
Coming soon
91
LongBench v2
49
92
MRCRv2
50

Knowledge

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

78.3

GPT-4o mini

62

97
MMLU
82
95
GPQA
Coming soon
93
SuperGPQA
Coming soon
91
OpenBookQA
Coming soon
88
MMLU-Pro
Coming soon
42
HLE
Coming soon
88
FrontierScience
62

Instruction Following

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

92
IFEval
Coming soon

Multilingual

GPT-5.3-Codex-Spark

GPT-5.3-Codex-Spark

90.8

GPT-4o mini

74.7

94
MGSM
87
89
MMLU-ProX
68

Mathematics

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

98
AIME 2023
Coming soon
98
AIME 2024
Coming soon
97
AIME 2025
Coming soon
94
HMMT Feb 2023
Coming soon
96
HMMT Feb 2024
Coming soon
95
HMMT Feb 2025
Coming soon
95
BRUMO 2025
Coming soon
98
MATH-500
Coming soon

Frequently Asked Questions

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

GPT-5.3-Codex-Spark is ahead overall, 87 to 52. The biggest single separator in this matchup is LongBench v2, where the scores are 91 and 49.

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

GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 62. Inside this category, FrontierScience is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 65. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 49.4. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 50.9. Inside this category, OSWorld-Verified 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 mini?

GPT-5.3-Codex-Spark has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 60.2. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

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

GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 74.7. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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