o3-mini vs Claude 3 Haiku

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

o3-mini is clearly ahead on the aggregate, 56 to 51. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

o3-mini's sharpest advantage is in knowledge, where it averages 82.1 against 47.2. The single biggest benchmark swing on the page is SWE-bench Verified, 49.3 to 17.

o3-mini is the reasoning model in the pair, while Claude 3 Haiku 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.

Quick Verdict

Pick o3-mini if you want the stronger benchmark profile. Claude 3 Haiku only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.

Knowledge

o3-mini

o3-mini

82.1

Claude 3 Haiku

47.2

86.9
MMLU
56
77.2
GPQA
56
-
SuperGPQA
54
-
OpenBookQA
52
-
MMLU-Pro
63
-
HLE
2

Coding

o3-mini

o3-mini

49.3

Claude 3 Haiku

28.3

49.3
SWE-bench Verified
17
-
HumanEval
48
-
LiveCodeBench
20

Mathematics

o3-mini

o3-mini

87.3

Claude 3 Haiku

57

87.3
AIME 2024
58
-
AIME 2023
56
-
AIME 2025
57
-
HMMT Feb 2023
52
-
HMMT Feb 2024
54
-
HMMT Feb 2025
53
-
BRUMO 2025
55
-
MATH-500
71

Reasoning

Claude 3 Haiku
-
SimpleQA
54
-
MuSR
52
-
BBH
74

Instruction Following

o3-mini

o3-mini

93.9

Claude 3 Haiku

76

93.9
IFEval
76

Multilingual

Claude 3 Haiku
-
MGSM
73

Frequently Asked Questions

Which is better, o3-mini or Claude 3 Haiku?

o3-mini is ahead overall, 56 to 51. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 49.3 and 17.

Which is better for knowledge tasks, o3-mini or Claude 3 Haiku?

o3-mini has the edge for knowledge tasks in this comparison, averaging 82.1 versus 47.2. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, o3-mini or Claude 3 Haiku?

o3-mini has the edge for coding in this comparison, averaging 49.3 versus 28.3. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, o3-mini or Claude 3 Haiku?

o3-mini has the edge for math in this comparison, averaging 87.3 versus 57. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for instruction following, o3-mini or Claude 3 Haiku?

o3-mini has the edge for instruction following in this comparison, averaging 93.9 versus 76. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Last updated: March 9, 2026

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