StepFun: Step 3.5 Flash (stepfun/step-3.5-flash) costs $0.1 per 1M prompt tokens and $0.3 per 1M completion tokens, has a 262,144-token context window, and supports tool calling and reasoning. Data updated 2026-10-30.
- Prompt price
- $0.1 / 1M tokens
- Completion price
- $0.3 / 1M tokens
- Context
- 262,144 tokens
- Input modalities
- text
- Output modalities
- text
- Tokenizer
- Other
- Instruct type
- —
- Knowledge cutoff
- —
- Hugging Face
- stepfun-ai/Step-3.5-Flash
Last price change: 2026-06-29
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....