Step 5 Preview
- Family
- Step
- Released
- 2026-09-20
- Context
- 1m
- Max output
- 64,000
- Parameters
- 600B (27B active)
- Architecture
- Mixture of Experts
- Specialization
- general
- Openness
- Proprietary
- License
- ProprietaryCommercial use: conditional
- Weights
- Coming soon
- Code
- Unknown
- Training
- Pretrained
Cheapest of 1 route · StepFun · cache read $0.050
About
Step 5 Preview is StepFun's flagship model for agentic work, aimed at software engineering and professional knowledge work, with particular strength in finance. It is a sparse Mixture-of-Experts model with 600B total parameters and 27B active per token. It accepts text, image, and video input, outputs text, and supports a 1M-token context window with up to 64K output tokens. Through the StepFun Open Platform API (model ID step-5-preview) it supports streaming, tool calling, JSON mode and JSON Schema structured output, prompt caching, and low/medium/high reasoning effort, via Chat Completions and Messages APIs.
Provider price ladder
Compare API pricing across 1 providers for input and output tokens, batch, and cached reads when available.
| Provider | Input / 1M | Output / 1M | Cache | Route |
|---|---|---|---|---|
| StepFun | $1.00 | $2.70 | read $0.050 | Serverless |
Capabilities
Benchmark peer barsfor RAG
No task-mapped benchmark peers are available for this model yet.
Migration checks
No linked migration route is available for this model yet.
API versions
step-5-previewStep 5 PreviewStep-5-PreviewCheapest of 1 route · StepFun · cache read $0.050