Model comparison

GPT-5.1 vs Step 3

GPT-5.1 is the stronger model overall, scoring 49.0 to 40.5 on the Noometry Index.

Last verified . 16 shared benchmarks.

GPT-5.1 OpenAI

49.0

Rank #53 Confirmed

Step 3 StepFun

40.5

Rank #149 Confirmed

Summary

  • They share 16 benchmarks with published results for both. GPT-5.1 scores higher in 9 categories and Step 3 in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.1 leads 52.2 to 37.6.
  • Step 3 has downloadable open weights; the other is API-only.

Side by side

GPT-5.1 and Step 3 specifications
GPT-5.1Step 3
ProviderOpenAIStepFun
Noometry Index49.040.5
Released2025-11-13—
WeightsProprietaryOpen
Context window400K—
Max output128K—
Input $ / M tokens$1.25—
Output $ / M tokens$10—
Results tracked6317

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Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.4 (#66), Step 3: 40.1 (#147)

Coding benchmarks
BenchmarkGPT-5.1Step 3
LMArena Coding14541367
SWE-bench Verified68%—
SWE-bench Verified (bash only)66%—
LMArena WebDev1395—
SciCode43.3%—
GSO13.7%—
WeirdML60.8%—
LiveBench Coding72.5%—
ALE-Bench1,192—

Agentic & Tool Use Not comparable

GPT-5.1: 32.7 (#60), Step 3: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1Step 3
Terminal-Bench47.6%—
DeepResearch Bench42.8%—
LMArena Search1199—
Vending-Bench 21,473—

Reasoning GPT-5.1 leads

GPT-5.1: 39.8 (#58), Step 3: 28.4 (#105)

Reasoning benchmarks
BenchmarkGPT-5.1Step 3
LMArena Hard Prompts14571355
ARC-AGI-217.6%—
SimpleBench53.2%—
Kagi LLM Benchmark—62.3%
ARC-AGI-172.8%—
CritPt4.9%—
Chess Puzzles32%—
EnigmaEval11.2%—
LiveBench Reasoning95.8%—
Mystery Game Puzzles19%—
DTBench90.1%—
LiveBench Data Analysis72.1%—
LMCA43.9%—
Epoch Capabilities Index149.64—
ForecastBench58.1—
LiveBench78.8%—

Math GPT-5.1 leads

GPT-5.1: 52.2 (#51), Step 3: 37.6 (#148)

Math benchmarks
BenchmarkGPT-5.1Step 3
LMArena Math14471366
OTIS Mock AIME 2024-202588.6%—
Omni-MATH46.4%—
LiveBench Math94.5%—
FrontierMath (Feb 2025 set)31%—
FrontierMath Tier 4 (v1)12.5%—

Knowledge GPT-5.1 leads

GPT-5.1: 50.6 (#71), Step 3: 36.8 (#164)

Knowledge benchmarks
BenchmarkGPT-5.1Step 3
LMArena Expert14701333
GPQA Diamond87.6%—
Humanity's Last Exam23.7%—
SimpleQA Verified48%—
MMLU-Pro57.9%—
Vectara Hallucination Rate10.9%—
GPQA (HELM)44.2%—

Multimodal GPT-5.1 leads

GPT-5.1: 44.8 (#19), Step 3: 35.5 (#86)

Multimodal benchmarks
BenchmarkGPT-5.1Step 3
LMArena Vision12501177
VPCT58.7%—
LMArena Document1403—

Multilingual GPT-5.1 leads

GPT-5.1: 53.8 (#56), Step 3: 46.3 (#159)

Multilingual benchmarks
BenchmarkGPT-5.1Step 3
LMArena Non-English14311327
LMArena Chinese14951397
LMArena German14381371
LMArena Korean14011269
LMArena Russian14351331
LMArena Spanish14331371
LMArena French1450—
LMArena Japanese1453—

Instruction Following GPT-5.1 leads

GPT-5.1: 83.9 (#1), Step 3: 70.4 (#164)

Instruction Following benchmarks
BenchmarkGPT-5.1Step 3
LMArena Instruction Following14431332
LiveBench Instruction Following93.3%—
IFEval93.5%—

Long Context GPT-5.1 leads

GPT-5.1: 47.6 (#14), Step 3: 40.3 (#157)

Long Context benchmarks
BenchmarkGPT-5.1Step 3
LMArena Longer Query14471326
CL-bench23.7%—
CL-bench Life17.3%—

Writing & Preference GPT-5.1 leads

GPT-5.1: 64.5 (#55), Step 3: 54.3 (#151)

Writing & Preference benchmarks
BenchmarkGPT-5.1Step 3
LMArena Text14431350
LMArena Creative Writing14271321
LMArena Multi-Turn14501341
WildBench86.3%—
LiveBench Language80.2%—

Frequently asked questions

Is GPT-5.1 better than Step 3?

GPT-5.1 is the stronger model overall, scoring 49.0 to 40.5 on the Noometry Index.

Is GPT-5.1 or Step 3 better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.4 versus 40.1 in the Noometry coding category.

How many benchmarks do GPT-5.1 and Step 3 share?

16 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and Step 3 has 17.

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