StepFun
Step 3.5 Flash 2603
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
ReleaseApr 2, 2026
Context262,144
Overall
Rank #162 across 566
26.0
Coding
No rank
n/a
Blended Price
Rank #34 across 371
$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
Output Speed256.9 tok/s
First Token0.74s
Max Output65,536
Pricing
Blended$0.150/M
Input$0.100/M
All Benchmarks
| Metric | Domain | Value | Rank |
|---|---|---|---|
| Artificial Analysis Intelligence Index | overall | 26.0 | #162 |
| GPQA | reasoning | 82.6% | #120 |
| Humanity's Last Exam | reasoning | 22.6% | #91 |
| SciCode | coding, reasoning | 38.5% | #172 |
| Output Speed |