Model comparison

o3-mini vs Step 3

Step 3 is the stronger model overall, scoring 40.5 to 36.7 on the Noometry Index.

Last verified . 15 shared benchmarks.

o3-mini OpenAI

36.7

Rank #212 Confirmed

Step 3 StepFun

40.5

Rank #149 Confirmed

Summary

  • They share 15 benchmarks with published results for both. o3-mini scores higher in 3 categories and Step 3 in 5 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Step 3 leads 28.4 to 16.3.
  • Step 3 has downloadable open weights; the other is API-only.

Side by side

o3-mini and Step 3 specifications
o3-miniStep 3
ProviderOpenAIStepFun
Noometry Index36.740.5
Released2024-12-20—
WeightsProprietaryOpen
Context window200K—
Max output100K—
Input $ / M tokens$1.10—
Output $ / M tokens$4.40—
Results tracked5117

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Category by category

Coding Too close to call

o3-mini: 40.8 (#132), Step 3: 40.1 (#147)

Coding benchmarks
Benchmarko3-miniStep 3
LMArena Coding13781367
Aider Polyglot60.4%—
SciCode39.8%—
GSO1.3%—
WeirdML43.7%—
LiveBench Coding82.7%—
CadEval54%—

Agentic & Tool Use Not comparable

o3-mini: 29.6 (#84), Step 3: —

Agentic & Tool Use benchmarks
Benchmarko3-miniStep 3
Cybench22.5%—

Reasoning Step 3 leads

o3-mini: 16.3 (#305), Step 3: 28.4 (#105)

Reasoning benchmarks
Benchmarko3-miniStep 3
LMArena Hard Prompts13661355
ARC-AGI-23%—
SimpleBench22.8%—
Kagi LLM Benchmark—62.3%
ARC-AGI-134.5%—
CritPt0.3%—
Chess Puzzles17%—
LiveBench Reasoning89.6%—
Mystery Game Puzzles7%—
DTBench68.8%—
LiveBench Data Analysis70.6%—
LMCA19%—
Epoch Capabilities Index140.34—
ForecastBench59.6—
LiveBench75.9%—

Math Step 3 leads

o3-mini: 28.1 (#244), Step 3: 37.6 (#148)

Knowledge o3-mini leads

o3-mini: 38.3 (#146), Step 3: 36.8 (#164)

Knowledge benchmarks
Benchmarko3-miniStep 3
LMArena Expert13641333
GPQA Diamond77%—
SimpleQA Verified15.3%—
Confabulations17.9%—

Multimodal Not comparable

o3-mini: —, Step 3: 35.5 (#86)

Multimodal benchmarks
Benchmarko3-miniStep 3
LMArena Vision—1177

Multilingual Too close to call

o3-mini: 45.7 (#164), Step 3: 46.3 (#159)

Multilingual benchmarks
Benchmarko3-miniStep 3
LMArena Non-English13191327
LMArena Chinese13791397
LMArena German13031371
LMArena Korean13141269
LMArena Russian13041331
LMArena Spanish13211371
LMArena French1334—
LMArena Japanese1286—

Instruction Following o3-mini leads

o3-mini: 75.1 (#72), Step 3: 70.4 (#164)

Instruction Following benchmarks
Benchmarko3-miniStep 3
LMArena Instruction Following13371332
LiveBench Instruction Following84.4%—

Long Context Step 3 leads

o3-mini: 33.8 (#256), Step 3: 40.3 (#157)

Long Context benchmarks
Benchmarko3-miniStep 3
LMArena Longer Query13431326
Fiction.LiveBench50%—

Writing & Preference Step 3 leads

o3-mini: 50.3 (#182), Step 3: 54.3 (#151)

Writing & Preference benchmarks
Benchmarko3-miniStep 3
LMArena Text13371350
LMArena Creative Writing12861321
LMArena Multi-Turn13201341
Short-Story Creative Writing61.7%—
LiveBench Language50.7%—

Frequently asked questions

Is o3-mini better than Step 3?

Step 3 is the stronger model overall, scoring 40.5 to 36.7 on the Noometry Index.

Is o3-mini or Step 3 better for coding?

They score almost the same on coding (40.8 vs 40.1); test both on your own repository before choosing.

How many benchmarks do o3-mini and Step 3 share?

15 benchmarks have published results for both models. o3-mini has 51 scored results on Noometry and Step 3 has 17.

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