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....
The figures
- Made by
- StepFun
- Model ID
- stepfun/step-3.5-flash
- Input
- $0.1 per million tokens
- Output
- $0.3 per million tokens
- Context window
- 262K tokens
- Longest answer
- 66K tokens
- Takes in
- text
- Gives back
- text
- Reasoning
- Yes
- Tool calling
- Yes
- Reads images
- No
- Open weights
- Yes
- Released
- 29 Jan 2026
Read on 3 Oct 2026.