StepFun
Step 5 Preview
Step 5 Preview is StepFun’s flagship AI model for agentic coding, professional knowledge work, and financial analysis. Built on a sparse Mixture-of-Experts architecture with 600B total parameters and 27B active per token, it combines a 1M-token context window with vision input. From building interactive applications and debugging code to conducting research and producing analytical reports, it supports complex workflows that require sustained reasoning, tool use, and iterative refinement.
StepFun researchModel Snapshot
TypeLanguage
ReleaseSep 20, 2026
Context1,000,000
Tagsimplicit-caching, vision, structured-output
Overall
Rank #39 across 687
43.7
Coding
No rank
n/a
Blended Price
Rank #249 across 432
$1.43/M
Strength Profile
Percentile score by analysis domain.
* Cost is inverted: lower input, output, and blended prices rank higher.
Benchmark Percentiles
Higher bars mean stronger relative placement.
Model Details
Runtime
Output Speed78.7 tok/s
First Token2.52s
Max Output1,000,000
Pricing
Blended$1.43/M
Input$1.00/M
All Benchmarks
| Metric | Domain | Value | Rank |
|---|---|---|---|
| Artificial Analysis Intelligence Index | overall | 43.7 | #39 |
| Humanity's Last Exam | reasoning | 46.5% | #32 |
| SciCode | coding, reasoning | 58.9% | #13 |
| Output Speed | speed | 78.7 tok/s | #103 |
| Time to First Token |