Step 3.5 Flash vs GPT-4.1

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

Step 3.5 Flash finishes one point ahead overall, 66 to 65. That is enough to call, but not enough to treat as a blowout. This matchup comes down to a few meaningful edges rather than one model dominating the board.

Step 3.5 Flash's sharpest advantage is in mathematics, where it averages 84.5 against 26.4. The single biggest benchmark swing on the page is AIME 2024, 87 to 26.4. GPT-4.1 does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.

GPT-4.1 is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.10 input / $0.30 output per 1M tokens for Step 3.5 Flash. That is roughly 26.7x on output cost alone. GPT-4.1 gives you the larger context window at 1M, compared with 256K for Step 3.5 Flash.

Quick Verdict

Pick Step 3.5 Flash if you want the stronger benchmark profile. GPT-4.1 only becomes the better choice if multimodal & grounded is the priority or you need the larger 1M context window.

Agentic

GPT-4.1

Step 3.5 Flash

60.2

GPT-4.1

64.7

62
Terminal-Bench 2.0
61
66
BrowseComp
73
54
OSWorld-Verified
63

Coding

GPT-4.1

Step 3.5 Flash

47.1

GPT-4.1

51.7

77
HumanEval
Coming soon
48
SWE-bench Verified
54.6
45
LiveCodeBench
Coming soon
49
SWE-bench Pro
51

Multimodal & Grounded

GPT-4.1

Step 3.5 Flash

66.7

GPT-4.1

73.6

64
MMMU-Pro
70
70
OfficeQA Pro
78

Reasoning

GPT-4.1

Step 3.5 Flash

78.3

GPT-4.1

80.9

82
SimpleQA
Coming soon
82
MuSR
Coming soon
83
BBH
Coming soon
74
LongBench v2
80
73
MRCRv2
82

Knowledge

GPT-4.1

Step 3.5 Flash

60.8

GPT-4.1

63.3

84
MMLU
90.2
83
GPQA
66.3
81
SuperGPQA
Coming soon
79
OpenBookQA
Coming soon
76
MMLU-Pro
Coming soon
12
HLE
Coming soon
71
FrontierScience
61

Instruction Following

GPT-4.1

Step 3.5 Flash

87

GPT-4.1

87.4

87
IFEval
87.4

Multilingual

Step 3.5 Flash

Step 3.5 Flash

82.8

GPT-4.1

69

86
MGSM
Coming soon
81
MMLU-ProX
69

Mathematics

Step 3.5 Flash

Step 3.5 Flash

84.5

GPT-4.1

26.4

85
AIME 2023
Coming soon
87
AIME 2024
26.4
86
AIME 2025
Coming soon
81
HMMT Feb 2023
Coming soon
83
HMMT Feb 2024
Coming soon
82
HMMT Feb 2025
Coming soon
84
BRUMO 2025
Coming soon
85
MATH-500
Coming soon

Frequently Asked Questions

Which is better, Step 3.5 Flash or GPT-4.1?

Step 3.5 Flash is ahead overall, 66 to 65. The biggest single separator in this matchup is AIME 2024, where the scores are 87 and 26.4.

Which is better for knowledge tasks, Step 3.5 Flash or GPT-4.1?

GPT-4.1 has the edge for knowledge tasks in this comparison, averaging 63.3 versus 60.8. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, Step 3.5 Flash or GPT-4.1?

GPT-4.1 has the edge for coding in this comparison, averaging 51.7 versus 47.1. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, Step 3.5 Flash or GPT-4.1?

Step 3.5 Flash has the edge for math in this comparison, averaging 84.5 versus 26.4. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Step 3.5 Flash or GPT-4.1?

GPT-4.1 has the edge for reasoning in this comparison, averaging 80.9 versus 78.3. Inside this category, MRCRv2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Step 3.5 Flash or GPT-4.1?

GPT-4.1 has the edge for agentic tasks in this comparison, averaging 64.7 versus 60.2. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Step 3.5 Flash or GPT-4.1?

GPT-4.1 has the edge for multimodal and grounded tasks in this comparison, averaging 73.6 versus 66.7. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Step 3.5 Flash or GPT-4.1?

GPT-4.1 has the edge for instruction following in this comparison, averaging 87.4 versus 87. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Step 3.5 Flash or GPT-4.1?

Step 3.5 Flash has the edge for multilingual tasks in this comparison, averaging 82.8 versus 69. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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