GPT-5 mini vs o3-mini

Side-by-side benchmark comparison across knowledge, coding, math, and reasoning.

GPT-5 mini is clearly ahead on the aggregate, 74 to 56. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5 mini's sharpest advantage is in coding, where it averages 52.7 against 49.3. The single biggest benchmark swing on the page is IFEval, 82 to 93.9. o3-mini does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.

o3-mini gives you the larger context window at 200K, compared with 128K for GPT-5 mini.

Quick Verdict

Pick GPT-5 mini if you want the stronger benchmark profile. o3-mini only becomes the better choice if instruction following is the priority or you need the larger 200K context window.

Knowledge

o3-mini

GPT-5 mini

71.5

o3-mini

82.1

88
MMLU
86.9
86
GPQA
77.2
84
SuperGPQA
-
82
OpenBookQA
-
73
MMLU-Pro
-
16
HLE
-

Coding

GPT-5 mini

GPT-5 mini

52.7

o3-mini

49.3

80
HumanEval
-
41
SWE-bench Verified
49.3
37
LiveCodeBench
-

Mathematics

GPT-5 mini

GPT-5 mini

88.5

o3-mini

87.3

90
AIME 2023
-
92
AIME 2024
87.3
91
AIME 2025
-
86
HMMT Feb 2023
-
88
HMMT Feb 2024
-
87
HMMT Feb 2025
-
89
BRUMO 2025
-
85
MATH-500
-

Reasoning

GPT-5 mini
84
SimpleQA
-
82
MuSR
-
87
BBH
-

Instruction Following

o3-mini

GPT-5 mini

82

o3-mini

93.9

82
IFEval
93.9

Multilingual

GPT-5 mini
82
MGSM
-

Frequently Asked Questions

Which is better, GPT-5 mini or o3-mini?

GPT-5 mini is ahead overall, 74 to 56. The biggest single separator in this matchup is IFEval, where the scores are 82 and 93.9.

Which is better for knowledge tasks, GPT-5 mini or o3-mini?

o3-mini has the edge for knowledge tasks in this comparison, averaging 82.1 versus 71.5. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5 mini or o3-mini?

GPT-5 mini has the edge for coding in this comparison, averaging 52.7 versus 49.3. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5 mini or o3-mini?

GPT-5 mini has the edge for math in this comparison, averaging 88.5 versus 87.3. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5 mini or o3-mini?

o3-mini has the edge for instruction following in this comparison, averaging 93.9 versus 82. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Last updated: March 9, 2026

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