Model comparison

Claude 3.7 Sonnet vs Step 3.5 Flash

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 39.5 on the Noometry Index.

Last verified . 17 shared benchmarks.

Claude 3.7 Sonnet Anthropic

39.5

Rank #164 Confirmed

Step 3.5 Flash StepFun

42.3

Rank #116 Confirmed

Summary

  • They share 17 benchmarks with published results for both. Claude 3.7 Sonnet scores higher in 2 categories and Step 3.5 Flash in 6 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in long context, where Claude 3.7 Sonnet leads 50.3 to 42.8.
  • Step 3.5 Flash has downloadable open weights; the other is API-only.

Side by side

Claude 3.7 Sonnet and Step 3.5 Flash specifications
Claude 3.7 SonnetStep 3.5 Flash
ProviderAnthropicStepFun
Noometry Index39.542.3
Released2025-02-242026-01-29
WeightsProprietaryOpen
Context window—256K
Max output—256K
Input $ / M tokens—$0.10
Output $ / M tokens—$0.30
Results tracked5819

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Category by category

Coding Step 3.5 Flash leads

Claude 3.7 Sonnet: 40.6 (#136), Step 3.5 Flash: 42.4 (#105)

Coding benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Coding13611436
SWE-bench Verified61%—
SWE-bench Verified (bash only)52.8%—
Aider Polyglot64.9%—
GSO3.8%—
LiveBench Coding74.5%—
CadEval54%—

Agentic & Tool Use Not comparable

Claude 3.7 Sonnet: 34.1 (#50), Step 3.5 Flash: —

Agentic & Tool Use benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
TheAgentCompany30.9%—
Cybench20%—
DeepResearch Bench43.6%—
OSWorld35.8%—
METR Time Horizons60%—

Reasoning Step 3.5 Flash leads

Claude 3.7 Sonnet: 18.6 (#277), Step 3.5 Flash: 22.2 (#202)

Reasoning benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Hard Prompts13331411
ARC-AGI-20.9%—
SimpleBench46.4%—
NYT Connections (extended)—28.4%
ARC-AGI-128.6%—
EnigmaEval4.2%—
LiveBench Reasoning87.8%—
LiveBench Data Analysis74%—
Epoch Capabilities Index141.16—
ForecastBench61.8—
LiveBench76.1%—

Math Step 3.5 Flash leads

Claude 3.7 Sonnet: 37.5 (#153), Step 3.5 Flash: 42.6 (#84)

Math benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Math13371408
MathArena Final-Answer Competitions—66.8%
OTIS Mock AIME 2024-202557.8%—
Omni-MATH33%—
LiveBench Math79%—
MATH Level 591.2%—
FrontierMath (Feb 2025 set)4.1%—

Knowledge Too close to call

Claude 3.7 Sonnet: 39.8 (#130), Step 3.5 Flash: 39.6 (#132)

Knowledge benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Expert13211421
GPQA Diamond79.7%—
Humanity's Last Exam8%—
MMLU-Pro78.4%—
Confabulations14.7%—
GPQA (HELM)60.8%—

Multimodal Not comparable

Claude 3.7 Sonnet: 33.7 (#95), Step 3.5 Flash: —

Multimodal benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Vision1169—
GeoBench68%—
VPCT39%—
SpatialViz-Bench33.9%—

Multilingual Step 3.5 Flash leads

Claude 3.7 Sonnet: 44.1 (#179), Step 3.5 Flash: 50.5 (#119)

Multilingual benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Non-English12961385
LMArena Chinese12991447
LMArena French13031421
LMArena German13011405
LMArena Japanese12671354
LMArena Korean12491352
LMArena Russian13111385
LMArena Spanish12981419

Instruction Following Too close to call

Claude 3.7 Sonnet: 72.9 (#125), Step 3.5 Flash: 73.1 (#124)

Instruction Following benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Instruction Following13521385
LiveBench Instruction Following81.3%—
IFEval83.4%—

Long Context Claude 3.7 Sonnet leads

Claude 3.7 Sonnet: 50.3 (#10), Step 3.5 Flash: 42.8 (#117)

Long Context benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Longer Query13731402
Fiction.LiveBench83.3%—

Writing & Preference Step 3.5 Flash leads

Claude 3.7 Sonnet: 54.4 (#150), Step 3.5 Flash: 58.8 (#113)

Writing & Preference benchmarks
BenchmarkClaude 3.7 SonnetStep 3.5 Flash
LMArena Text13141403
LMArena Creative Writing13321357
LMArena Multi-Turn13391405
Short-Story Creative Writing81.1%—
EQ-Bench Creative Writing1412—
WildBench81.4%—
LiveBench Language59.9%—

Frequently asked questions

Is Claude 3.7 Sonnet better than Step 3.5 Flash?

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 39.5 on the Noometry Index.

Is Claude 3.7 Sonnet or Step 3.5 Flash better for coding?

Step 3.5 Flash scores higher on coding benchmarks: 42.4 versus 40.6 in the Noometry coding category.

How many benchmarks do Claude 3.7 Sonnet and Step 3.5 Flash share?

17 benchmarks have published results for both models. Claude 3.7 Sonnet has 58 scored results on Noometry and Step 3.5 Flash has 19.

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