Model comparison
Claude Opus 4.1 vs Step 5 Preview
Step 5 Preview is the stronger model overall, scoring 43.8 to 40.8 on the Noometry Index.
Last verified . 1 shared benchmarks.
StepFunSummary
- They share 1 benchmark with published results for both. Claude Opus 4.1 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 31.6.
- Step 5 Preview is cheaper at $1 / $2.70 per million input/output tokens, against $15 / $75 for Claude Opus 4.1.
- Step 5 Preview accepts more context: 1.02M tokens versus 200K.
Side by side
| Claude Opus 4.1 | Step 5 Preview | |
|---|---|---|
| Provider | Anthropic | StepFun |
| Noometry Index | 40.8 | 43.8 |
| Released | 2025-08-05 | 2026-09-16 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 1.02M |
| Max output | 32K | 66K |
| Input $ / M tokens | $15 | $1 |
| Output $ / M tokens | $75 | $2.70 |
| Results tracked | 48 | 3 |
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Category by category
Coding Step 5 Preview leads
Claude Opus 4.1: 44.3 (#69), Step 5 Preview: 50.6 (#40)
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| LMArena WebDev | 1390 | 1569 |
| SWE-bench Verified | 73.3% | — |
| SciCode | — | 58.9% |
| WeirdML | 45.9% | — |
| LMArena Coding | 1479 | — |
| ALE-Bench | 674.77 | — |
| AlgoTune | 1.34 | — |
Agentic & Tool Use Not comparable
Claude Opus 4.1: 34.8 (#38), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| Terminal-Bench | 38% | — |
| GDPval | 43.6% | — |
| Cybench | 42% | — |
| DeepResearch Bench | 48.3% | — |
| LMArena Search | 1148 | — |
| METR Time Horizons | 66.8% | — |
Reasoning Step 5 Preview leads
Claude Opus 4.1: 31.6 (#70), Step 5 Preview: 38.0 (#58)
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| SimpleBench | 60% | — |
| CritPt | — | 20.9% |
| Chess Puzzles | 7% | — |
| EnigmaEval | 7.2% | — |
| EBR-Bench | 7.9% | — |
| LMArena Hard Prompts | 1443 | — |
| Mystery Game Puzzles | 21% | — |
| DTBench | 80% | — |
| LMCA | 37.1% | — |
| Epoch Capabilities Index | 144.11 | — |
| ForecastBench | 62 | — |
Math Not comparable
Claude Opus 4.1: 22.0 (#267), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| FrontierMath (Tiers 1-3) | 12.6% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 68.9% | — |
| LMArena Math | 1430 | — |
| FrontierMath (Feb 2025 set) | 7.2% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Not comparable
Claude Opus 4.1: 41.9 (#93), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| GPQA Diamond | 77.3% | — |
| Humanity's Last Exam | 11.5% | — |
| Confabulations | 17.1% | — |
| Vectara Hallucination Rate | 11.8% | — |
| LMArena Expert | 1439 | — |
Multimodal Not comparable
Claude Opus 4.1: 26.2 (#114), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| VPCT | 35% | — |
Multilingual Not comparable
Claude Opus 4.1: 52.1 (#90), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| LMArena Non-English | 1405 | — |
| LMArena Chinese | 1427 | — |
| LMArena French | 1432 | — |
| LMArena German | 1412 | — |
| LMArena Japanese | 1378 | — |
| LMArena Korean | 1381 | — |
| LMArena Russian | 1421 | — |
| LMArena Spanish | 1448 | — |
Instruction Following Not comparable
Claude Opus 4.1: 75.8 (#53), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| LMArena Instruction Following | 1436 | — |
Long Context Not comparable
Claude Opus 4.1: 44.5 (#60), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| LMArena Longer Query | 1455 | — |
Writing & Preference Not comparable
Claude Opus 4.1: 62.6 (#70), Step 5 Preview: —
| Benchmark | Claude Opus 4.1 | Step 5 Preview |
|---|---|---|
| LMArena Text | 1419 | — |
| LMArena Creative Writing | 1412 | — |
| Short-Story Creative Writing | 84.7% | — |
| LMArena Multi-Turn | 1444 | — |
Frequently asked questions
Is Claude Opus 4.1 better than Step 5 Preview?
Step 5 Preview is the stronger model overall, scoring 43.8 to 40.8 on the Noometry Index.
Which is cheaper, Claude Opus 4.1 or Step 5 Preview?
Step 5 Preview is cheaper. It lists at $1 per million input tokens and $2.70 per million output tokens; Claude Opus 4.1 lists at $15 and $75.
Is Claude Opus 4.1 or Step 5 Preview better for coding?
Step 5 Preview scores higher on coding benchmarks: 50.6 versus 44.3 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 Claude Opus 4.1 and Step 5 Preview share?
1 benchmark has published results for both models. Claude Opus 4.1 has 48 scored results on Noometry and Step 5 Preview has 3.