SFAI / MODEL PROFILE
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....
- Developer
- stepfun
- Input modalities
- text
- Output modalities
- text
- Context tokens
- 262,144
- Latest price observation
- 2026-09-28
- Lowest paired standard token quote
- $0.10 input / $0.30 output per 1M tokens
Dated price and provider records
| Provider and channel | Input | Output or native rate | Unit and status | Source and observation |
|---|---|---|---|---|
| Automatic routingopenrouter | $0.10 | $0.30 | 1M tokenspriced · USD | openrouter2026-09-28 |
These are dated, non-executable observations. Verify the exact endpoint, price and terms with the source before use. Unknown values are not free.