Claude Haiku 4.5 vs GPT-4.1 nano

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

Claude Haiku 4.5 is clearly ahead on the aggregate, 64 to 23. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Haiku 4.5's sharpest advantage is in mathematics, where it averages 68.8 against 9.8. The single biggest benchmark swing on the page is AIME 2024, 70 to 9.8. GPT-4.1 nano does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

Claude Haiku 4.5 is also the more expensive model on tokens at $0.80 input / $4.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for GPT-4.1 nano. That is roughly 10.0x on output cost alone. GPT-4.1 nano gives you the larger context window at 1M, compared with 200K for Claude Haiku 4.5.

Quick Verdict

Pick Claude Haiku 4.5 if you want the stronger benchmark profile. GPT-4.1 nano only becomes the better choice if knowledge is the priority or you want the cheaper token bill.

Knowledge

GPT-4.1 nano

Claude Haiku 4.5

57.8

GPT-4.1 nano

65.2

68
MMLU
80.1
67
GPQA
50.3
65
SuperGPQA
-
63
OpenBookQA
-
73
MMLU-Pro
-
11
HLE
-

Coding

Claude Haiku 4.5
60
HumanEval
-
48
SWE-bench Verified
-
36
LiveCodeBench
-

Mathematics

Claude Haiku 4.5

Claude Haiku 4.5

68.8

GPT-4.1 nano

9.8

68
AIME 2023
-
70
AIME 2024
9.8
69
AIME 2025
-
64
HMMT Feb 2023
-
66
HMMT Feb 2024
-
65
HMMT Feb 2025
-
67
BRUMO 2025
-
81
MATH-500
-

Reasoning

Claude Haiku 4.5
65
SimpleQA
-
63
MuSR
-
81
BBH
-

Instruction Following

Claude Haiku 4.5

Claude Haiku 4.5

86

GPT-4.1 nano

83.2

86
IFEval
83.2

Multilingual

Claude Haiku 4.5
82
MGSM
-

Frequently Asked Questions

Which is better, Claude Haiku 4.5 or GPT-4.1 nano?

Claude Haiku 4.5 is ahead overall, 64 to 23. The biggest single separator in this matchup is AIME 2024, where the scores are 70 and 9.8.

Which is better for knowledge tasks, Claude Haiku 4.5 or GPT-4.1 nano?

GPT-4.1 nano has the edge for knowledge tasks in this comparison, averaging 65.2 versus 57.8. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for math, Claude Haiku 4.5 or GPT-4.1 nano?

Claude Haiku 4.5 has the edge for math in this comparison, averaging 68.8 versus 9.8. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for instruction following, Claude Haiku 4.5 or GPT-4.1 nano?

Claude Haiku 4.5 has the edge for instruction following in this comparison, averaging 86 versus 83.2. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Last updated: March 9, 2026

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