Noometry

Model comparison

Mistral Small 3.1 vs Step 3.5 Flash

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 31.7 on the Noometry Index.

Last verified . 17 shared benchmarks.

Mistral Small 3.1 Mistral AI

31.7

Rank #269 Confirmed

Step 3.5 Flash StepFun

42.3

Rank #116 Confirmed

Summary

  • They share 17 benchmarks with published results for both. Mistral Small 3.1 scores higher in 0 categories and Step 3.5 Flash in 8 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where Step 3.5 Flash leads 42.6 to 14.7.
  • Step 3.5 Flash is cheaper at $0.10 / $0.30 per million input/output tokens, against $0.35 / $0.56 for Mistral Small 3.1.
  • Step 3.5 Flash accepts more context: 256K tokens versus 128K.

Side by side

Mistral Small 3.1Step 3.5 Flash
ProviderMistral AIStepFun
Noometry Index31.742.3
Released2025-03-172026-01-29
WeightsOpenOpen
Context window128K256K
Max output102K256K
Input $ / M tokens$0.35$0.10
Output $ / M tokens$0.56$0.30
Results tracked2819

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Category by category

Coding Step 3.5 Flash leads

Mistral Small 3.1: 38.3 (#179), Step 3.5 Flash: 42.4 (#105)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Coding13091436

Reasoning Step 3.5 Flash leads

Mistral Small 3.1: 19.7 (#254), Step 3.5 Flash: 22.2 (#202)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Hard Prompts12781411
NYT Connections (extended)—28.4%
Chess Puzzles1%—
Epoch Capabilities Index127.48—

Math Step 3.5 Flash leads

Mistral Small 3.1: 14.7 (#301), Step 3.5 Flash: 42.6 (#84)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Math12621408
MathArena Final-Answer Competitions—66.8%
OTIS Mock AIME 2024-20253.9%—
Omni-MATH24.8%—

Knowledge Step 3.5 Flash leads

Mistral Small 3.1: 22.6 (#271), Step 3.5 Flash: 39.6 (#132)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Expert12571421
GPQA Diamond41.9%—
MMLU-Pro61%—
GPQA (HELM)39.2%—

Multimodal Not comparable

Mistral Small 3.1: 33.2 (#99), Step 3.5 Flash: —

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Vision1136—

Multilingual Step 3.5 Flash leads

Mistral Small 3.1: 41.2 (#209), Step 3.5 Flash: 50.5 (#119)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Non-English12551385
LMArena Chinese12531447
LMArena French12731421
LMArena German12661405
LMArena Japanese12081354
LMArena Korean12061352
LMArena Russian12631385
LMArena Spanish12831419

Instruction Following Step 3.5 Flash leads

Mistral Small 3.1: 63.6 (#230), Step 3.5 Flash: 73.1 (#124)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Instruction Following12641385
IFEval75%—

Long Context Step 3.5 Flash leads

Mistral Small 3.1: 39.5 (#178), Step 3.5 Flash: 42.8 (#117)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Longer Query12991402

Writing & Preference Step 3.5 Flash leads

Mistral Small 3.1: 37.0 (#259), Step 3.5 Flash: 58.8 (#113)

BenchmarkMistral Small 3.1Step 3.5 Flash
LMArena Text12771403
LMArena Creative Writing12531357
LMArena Multi-Turn12701405
EQ-Bench Creative Writing761—
WildBench78.8%—

Frequently asked questions

Is Mistral Small 3.1 better than Step 3.5 Flash?

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 31.7 on the Noometry Index.

Which is cheaper, Mistral Small 3.1 or Step 3.5 Flash?

Step 3.5 Flash is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Mistral Small 3.1 lists at $0.35 and $0.56.

Is Mistral Small 3.1 or Step 3.5 Flash better for coding?

Step 3.5 Flash scores higher on coding benchmarks: 42.4 versus 38.3 in the Noometry coding category.

Which has the bigger context window?

Step 3.5 Flash does, with 256K tokens against 128K.

How many benchmarks do Mistral Small 3.1 and Step 3.5 Flash share?

17 benchmarks have published results for both models. Mistral Small 3.1 has 28 scored results on Noometry and Step 3.5 Flash has 19.

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