StepFun
Step 3.5 Flash
Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....
StepFun researchModel Snapshot
ReleaseFeb 2, 2026
Context262,144
Overall
Rank #197 across 600
25.5
Coding
No rank
n/a
Blended Price
Rank #42 across 379
$0.150/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
Max Output65,536
Streaming speed is not measured for this model yet.
Pricing
Blended$0.150/M
Input$0.100/M
Output$0.300/M
Metadata
Modalities
All Benchmarks
| Metric | Domain | Value | Rank |
|---|---|---|---|
| Artificial Analysis Intelligence Index | overall | 25.5 | #197 |
| GPQA | reasoning | 83.1% | #124 |
| Humanity's Last Exam | reasoning | 19.1% | #123 |
| SciCode | coding, reasoning | 40.4% | #145 |
| Blended Price |