Model comparison
o3-mini vs Step 5 Preview
Step 5 Preview is the stronger model overall, scoring 43.8 to 36.7 on the Noometry Index.
Last verified . 2 shared benchmarks.
StepFunSummary
- They share 2 benchmarks with published results for both. o3-mini scores higher in 0 categories and Step 5 Preview in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Step 5 Preview leads 38.0 to 16.3.
- The biggest single-benchmark swing is CritPt: 0.3% for o3-mini and 20.9% for Step 5 Preview.
- Step 5 Preview is cheaper at $1 / $2.70 per million input/output tokens, against $1.10 / $4.40 for o3-mini.
- Step 5 Preview accepts more context: 1.02M tokens versus 200K.
Side by side
| o3-mini | Step 5 Preview | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 36.7 | 43.8 |
| Released | 2024-12-20 | 2026-09-16 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 1.02M |
| Max output | 100K | 66K |
| Input $ / M tokens | $1.10 | $1 |
| Output $ / M tokens | $4.40 | $2.70 |
| Results tracked | 51 | 3 |
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Category by category
Coding Step 5 Preview leads
o3-mini: 41.4 (#116), Step 5 Preview: 50.6 (#40)
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| SciCode | 39.8% | 58.9% |
| Aider Polyglot | 60.4% | — |
| LMArena WebDev | — | 1569 |
| GSO | 1.3% | — |
| WeirdML | 43.7% | — |
| LiveBench Coding | 82.7% | — |
| LMArena Coding | 1378 | — |
| CadEval | 54% | — |
Agentic & Tool Use Not comparable
o3-mini: 29.3 (#79), Step 5 Preview: —
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| Cybench | 22.5% | — |
Reasoning Step 5 Preview leads
o3-mini: 16.3 (#295), Step 5 Preview: 38.0 (#58)
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| CritPt | 0.3% | 20.9% |
| ARC-AGI-2 | 3% | — |
| SimpleBench | 22.8% | — |
| ARC-AGI-1 | 34.5% | — |
| Chess Puzzles | 17% | — |
| LiveBench Reasoning | 89.6% | — |
| LMArena Hard Prompts | 1366 | — |
| Mystery Game Puzzles | 7% | — |
| DTBench | 68.8% | — |
| LiveBench Data Analysis | 70.6% | — |
| LMCA | 19% | — |
| Epoch Capabilities Index | 140.35 | — |
| ForecastBench | 59.6 | — |
| LiveBench | 75.9% | — |
Math Not comparable
o3-mini: 27.6 (#236), Step 5 Preview: —
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| FrontierMath (Tiers 1-3) | 18.6% | — |
| FrontierMath Tier 4 | 0% | — |
| OTIS Mock AIME 2024-2025 | 76.9% | — |
| LiveBench Math | 77.3% | — |
| LMArena Math | 1396 | — |
| MATH Level 5 | 96.5% | — |
| FrontierMath (Feb 2025 set) | 12.4% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Not comparable
o3-mini: 38.3 (#135), Step 5 Preview: —
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| GPQA Diamond | 77% | — |
| SimpleQA Verified | 15.3% | — |
| Confabulations | 17.9% | — |
| LMArena Expert | 1364 | — |
Multilingual Not comparable
o3-mini: 45.9 (#159), Step 5 Preview: —
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| LMArena Non-English | 1319 | — |
| LMArena Chinese | 1379 | — |
| LMArena French | 1333 | — |
| LMArena German | 1303 | — |
| LMArena Japanese | 1286 | — |
| LMArena Korean | 1314 | — |
| LMArena Russian | 1304 | — |
| LMArena Spanish | 1321 | — |
Instruction Following Not comparable
o3-mini: 75.3 (#67), Step 5 Preview: —
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| LiveBench Instruction Following | 84.4% | — |
| LMArena Instruction Following | 1338 | — |
Long Context Not comparable
o3-mini: 33.8 (#251), Step 5 Preview: —
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| Fiction.LiveBench | 50% | — |
| LMArena Longer Query | 1343 | — |
Writing & Preference Not comparable
o3-mini: 50.4 (#177), Step 5 Preview: —
| Benchmark | o3-mini | Step 5 Preview |
|---|---|---|
| LMArena Text | 1337 | — |
| LMArena Creative Writing | 1286 | — |
| Short-Story Creative Writing | 61.7% | — |
| LMArena Multi-Turn | 1320 | — |
| LiveBench Language | 50.7% | — |
Frequently asked questions
Is o3-mini better than Step 5 Preview?
Step 5 Preview is the stronger model overall, scoring 43.8 to 36.7 on the Noometry Index.
Which is cheaper, o3-mini or Step 5 Preview?
Step 5 Preview is cheaper. It lists at $1 per million input tokens and $2.70 per million output tokens; o3-mini lists at $1.10 and $4.40.
Is o3-mini or Step 5 Preview better for coding?
Step 5 Preview scores higher on coding benchmarks: 50.6 versus 41.4 in the Noometry coding category.
Which has the bigger context window?
Step 5 Preview does, with 1.02M tokens against 200K.
How many benchmarks do o3-mini and Step 5 Preview share?
2 benchmarks have published results for both models. o3-mini has 51 scored results on Noometry and Step 5 Preview has 3.