Step 5 Preview
StepFun’s new agentic flagship — 600B MoE with video input.
Step 5 Preview is StepFun’s flagship model for agentic work, built on a sparse mixture-of-experts architecture (27B active / 600B total). It performs strongly in software engineering and professional tasks.
- Provider
- StepFun
- Type
- Language model
- Released
- Oct 8, 2026
- Context window
- 1M tokens
- Max output
- 64K tokens
- Price
- $1.00 input / $2.70 output per 1M tokens
- Input
- text, image, video
- Output
- text
- Open weights
- No
Best for
- Agents
- Coding
- Multimodal
Strengths
- Fast first token
- Video input
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