Noometry

Model comparison

GPT-4.1 nano vs Step 3.5 Flash

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 27.9 on the Noometry Index.

Last verified . 14 shared benchmarks.

GPT-4.1 nano OpenAI

27.9

Rank #327 Confirmed

Step 3.5 Flash StepFun

42.3

Rank #116 Confirmed

Summary

  • They share 14 benchmarks with published results for both. GPT-4.1 nano 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 long context, where Step 3.5 Flash leads 42.8 to 23.7.
  • Step 3.5 Flash is cheaper at $0.10 / $0.30 per million input/output tokens, against $0.10 / $0.40 for GPT-4.1 nano.
  • GPT-4.1 nano accepts more context: 1.05M tokens versus 256K.
  • Step 3.5 Flash has downloadable open weights; the other is API-only.

Side by side

GPT-4.1 nanoStep 3.5 Flash
ProviderOpenAIStepFun
Noometry Index27.942.3
Released2025-04-142026-01-29
WeightsProprietaryOpen
Context window1.05M256K
Max output33K256K
Input $ / M tokens$0.10$0.10
Output $ / M tokens$0.40$0.30
Results tracked3819

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Category by category

Coding Step 3.5 Flash leads

GPT-4.1 nano: 24.1 (#330), Step 3.5 Flash: 42.4 (#105)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Coding13061436
Aider Polyglot8.9%—
SciCode25.9%—
WeirdML19%—

Agentic & Tool Use Not comparable

GPT-4.1 nano: 26.5 (#104), Step 3.5 Flash: —

BenchmarkGPT-4.1 nanoStep 3.5 Flash
Berkeley Function Calling Leaderboard33%—

Reasoning Step 3.5 Flash leads

GPT-4.1 nano: 8.5 (#349), Step 3.5 Flash: 22.2 (#202)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Hard Prompts12861411
ARC-AGI-20%—
Kagi LLM Benchmark33.3%—
NYT Connections (extended)—28.4%
ARC-AGI-10%—
CritPt0%—
DTBench52.5%—
LMCA5.5%—
Epoch Capabilities Index129.62—

Math Step 3.5 Flash leads

GPT-4.1 nano: 26.9 (#252), Step 3.5 Flash: 42.6 (#84)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Math12741408
MathArena Final-Answer Competitions—66.8%
OTIS Mock AIME 2024-202528.9%—
Omni-MATH36.7%—
MATH Level 570%—
FrontierMath (Feb 2025 set)1%—

Knowledge Step 3.5 Flash leads

GPT-4.1 nano: 21.8 (#273), Step 3.5 Flash: 39.6 (#132)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Expert12721421
GPQA Diamond48.9%—
SimpleQA Verified6%—
MMLU-Pro55%—
GPQA (HELM)50.7%—

Multimodal Not comparable

GPT-4.1 nano: 29.2 (#113), Step 3.5 Flash: —

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Vision1063—

Multilingual Step 3.5 Flash leads

GPT-4.1 nano: 41.6 (#205), Step 3.5 Flash: 50.5 (#119)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Non-English12601385
LMArena Chinese12701447
LMArena German12881405
LMArena Japanese11981354
LMArena Russian12611385
LMArena French—1421
LMArena Korean—1352
LMArena Spanish—1419

Instruction Following Step 3.5 Flash leads

GPT-4.1 nano: 67.8 (#193), Step 3.5 Flash: 73.1 (#124)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Instruction Following12671385
IFEval84.3%—

Long Context Step 3.5 Flash leads

GPT-4.1 nano: 23.7 (#296), Step 3.5 Flash: 42.8 (#117)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Longer Query12831402
Fiction.LiveBench25%—

Writing & Preference Step 3.5 Flash leads

GPT-4.1 nano: 40.5 (#243), Step 3.5 Flash: 58.8 (#113)

BenchmarkGPT-4.1 nanoStep 3.5 Flash
LMArena Text12851403
LMArena Creative Writing12601357
LMArena Multi-Turn12771405
EQ-Bench Creative Writing946—
WildBench81.2%—

Frequently asked questions

Is GPT-4.1 nano better than Step 3.5 Flash?

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 27.9 on the Noometry Index.

Which is cheaper, GPT-4.1 nano 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; GPT-4.1 nano lists at $0.10 and $0.40.

Is GPT-4.1 nano or Step 3.5 Flash better for coding?

Step 3.5 Flash scores higher on coding benchmarks: 42.4 versus 24.1 in the Noometry coding category.

Which has the bigger context window?

GPT-4.1 nano does, with 1.05M tokens against 256K.

How many benchmarks do GPT-4.1 nano and Step 3.5 Flash share?

14 benchmarks have published results for both models. GPT-4.1 nano has 38 scored results on Noometry and Step 3.5 Flash has 19.

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