Step 3.5 Flash vs Mistral Large 3

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

Step 3.5 Flash is clearly ahead on the aggregate, 66 to 61. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Step 3.5 Flash's sharpest advantage is in agentic, where it averages 60.2 against 52.5. The single biggest benchmark swing on the page is MMMU-Pro, 64 to 75. Mistral Large 3 does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.

Mistral Large 3 is also the more expensive model on tokens at $2.00 input / $6.00 output per 1M tokens, versus $0.10 input / $0.30 output per 1M tokens for Step 3.5 Flash. That is roughly 20.0x on output cost alone. Step 3.5 Flash gives you the larger context window at 256K, compared with 128K for Mistral Large 3.

Quick Verdict

Pick Step 3.5 Flash if you want the stronger benchmark profile. Mistral Large 3 only becomes the better choice if multimodal & grounded is the priority.

Agentic

Step 3.5 Flash

Step 3.5 Flash

60.2

Mistral Large 3

52.5

62
Terminal-Bench 2.0
52
66
BrowseComp
58
54
OSWorld-Verified
49

Coding

Step 3.5 Flash

Step 3.5 Flash

47.1

Mistral Large 3

41

77
HumanEval
68
48
SWE-bench Verified
45
45
LiveCodeBench
39
49
SWE-bench Pro
42

Multimodal & Grounded

Mistral Large 3

Step 3.5 Flash

66.7

Mistral Large 3

75.5

64
MMMU-Pro
75
70
OfficeQA Pro
76

Reasoning

Step 3.5 Flash

Step 3.5 Flash

78.3

Mistral Large 3

70.6

82
SimpleQA
73
82
MuSR
71
83
BBH
81
74
LongBench v2
67
73
MRCRv2
67

Knowledge

Step 3.5 Flash

Step 3.5 Flash

60.8

Mistral Large 3

57.1

84
MMLU
76
83
GPQA
75
81
SuperGPQA
73
79
OpenBookQA
71
76
MMLU-Pro
74
12
HLE
12
71
FrontierScience
67

Instruction Following

Step 3.5 Flash

Step 3.5 Flash

87

Mistral Large 3

83

87
IFEval
83

Multilingual

Step 3.5 Flash

Step 3.5 Flash

82.8

Mistral Large 3

78.8

86
MGSM
82
81
MMLU-ProX
77

Mathematics

Step 3.5 Flash

Step 3.5 Flash

84.5

Mistral Large 3

77.3

85
AIME 2023
76
87
AIME 2024
78
86
AIME 2025
77
81
HMMT Feb 2023
72
83
HMMT Feb 2024
74
82
HMMT Feb 2025
73
84
BRUMO 2025
75
85
MATH-500
80

Frequently Asked Questions

Which is better, Step 3.5 Flash or Mistral Large 3?

Step 3.5 Flash is ahead overall, 66 to 61. The biggest single separator in this matchup is MMMU-Pro, where the scores are 64 and 75.

Which is better for knowledge tasks, Step 3.5 Flash or Mistral Large 3?

Step 3.5 Flash has the edge for knowledge tasks in this comparison, averaging 60.8 versus 57.1. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Step 3.5 Flash or Mistral Large 3?

Step 3.5 Flash has the edge for coding in this comparison, averaging 47.1 versus 41. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Step 3.5 Flash or Mistral Large 3?

Step 3.5 Flash has the edge for math in this comparison, averaging 84.5 versus 77.3. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Step 3.5 Flash or Mistral Large 3?

Step 3.5 Flash has the edge for reasoning in this comparison, averaging 78.3 versus 70.6. Inside this category, MuSR is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Step 3.5 Flash or Mistral Large 3?

Step 3.5 Flash has the edge for agentic tasks in this comparison, averaging 60.2 versus 52.5. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Step 3.5 Flash or Mistral Large 3?

Mistral Large 3 has the edge for multimodal and grounded tasks in this comparison, averaging 75.5 versus 66.7. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Step 3.5 Flash or Mistral Large 3?

Step 3.5 Flash has the edge for instruction following in this comparison, averaging 87 versus 83. 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 Mistral Large 3?

Step 3.5 Flash has the edge for multilingual tasks in this comparison, averaging 82.8 versus 78.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

Weekly LLM Benchmark Digest

Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.

Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.