Claude 3.5 Sonnet vs o1

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

Claude 3.5 Sonnet is clearly ahead on the aggregate, 62 to 51. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude 3.5 Sonnet's sharpest advantage is in coding, where it averages 44 against 41. The single biggest benchmark swing on the page is MMLU, 65 to 91.8. o1 does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

o1 is the reasoning model in the pair, while Claude 3.5 Sonnet 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 Claude 3.5 Sonnet if you want the stronger benchmark profile. o1 only becomes the better choice if knowledge is the priority or you want the stronger reasoning-first profile.

Knowledge

o1

Claude 3.5 Sonnet

55.5

o1

83.8

65
MMLU
91.8
65
GPQA
75.7
63
SuperGPQA
-
61
OpenBookQA
-
74
MMLU-Pro
-
5
HLE
-

Coding

Claude 3.5 Sonnet

Claude 3.5 Sonnet

44

o1

41

57
HumanEval
-
36
SWE-bench Verified
41
39
LiveCodeBench
-

Mathematics

o1

Claude 3.5 Sonnet

66

o1

74.3

65
AIME 2023
-
67
AIME 2024
74.3
66
AIME 2025
-
61
HMMT Feb 2023
-
63
HMMT Feb 2024
-
62
HMMT Feb 2025
-
64
BRUMO 2025
-
80
MATH-500
-

Reasoning

Claude 3.5 Sonnet
63
SimpleQA
-
61
MuSR
-
83
BBH
-

Instruction Following

o1

Claude 3.5 Sonnet

83

o1

92.2

83
IFEval
92.2

Multilingual

Claude 3.5 Sonnet
85
MGSM
-

Frequently Asked Questions

Which is better, Claude 3.5 Sonnet or o1?

Claude 3.5 Sonnet is ahead overall, 62 to 51. The biggest single separator in this matchup is MMLU, where the scores are 65 and 91.8.

Which is better for knowledge tasks, Claude 3.5 Sonnet or o1?

o1 has the edge for knowledge tasks in this comparison, averaging 83.8 versus 55.5. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Claude 3.5 Sonnet or o1?

Claude 3.5 Sonnet has the edge for coding in this comparison, averaging 44 versus 41. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, Claude 3.5 Sonnet or o1?

o1 has the edge for math in this comparison, averaging 74.3 versus 66. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for instruction following, Claude 3.5 Sonnet or o1?

o1 has the edge for instruction following in this comparison, averaging 92.2 versus 83. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Last updated: March 9, 2026

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