StepFun is a Shanghai-based AI company founded in April 2023 by Jiang Daxin, Zhu Yibo and Jiao Binxing. It develops the Step series of language and multimodal models, including Step 3.5 Flash.
- Founded
- 2023
- Type
- Private company
- Founders
- Jiang Daxin, Zhu Yibo and Jiao Binxing
- AI lab
- Inference provider
- 3 hosted endpoints
| Model | Endpoint | Context | Input /M | Output /M | Cached input /M | Cache write /M | Uptime 1d |
|---|---|---|---|---|---|---|---|
 DeepSeek V4.1 Flash 1017 | stepfun/fp8 | 1M | $0.105 | $0.42 | $0.0021 | — | 98.64% |
 Step 3.7 Flash | stepfun/fp8 | 256K | $0.20 | $1.15 | $0.04 | — | 100.00% |
| Step 5 Preview | stepfun/fp8 | 1M | $1.00 | $2.70 | $0.10 | — | 100.00% |