Step 5 Preview
StepFun released Step 5 Preview, a 600B-total, 27B-active sparse MoE model for agentic work, with a 1M token context, on OpenRouter at $1 input and $2.70 output per million tokens.
Step 5 Preview is StepFun's flagship agentic model, larger than the 196B-total Step 3.5 Flash and Step 3.7 Flash models. It is aimed at software engineering and professional knowledge work, with a stated strength in finance, and at long tasks across large codebases and documents using tools over multiple steps. It accepts text, images and video as input and returns text.
- Date
- Thursday 8 October 2026
- Lab
- StepFun
- Kind
- model
- Access
- closed API
- Price
- $1.00 per 1M input tokens, $2.70 per 1M output tokens
Figures
| Measure | Value | Measured by |
|---|---|---|
| Total parameters | 600B sparse Mixture-of-Experts | company |
| Active parameters | 27B per token | company |
| Context window | 1,000,000 tokens up to 64,000 completion tokens | company |
| Cache read price | $0.05 per 1M tokens OpenRouter listing | company |
Based only on the OpenRouter listing, which was the only provider (StepFun). No benchmarks or open weights were mentioned on the page.
Sources
This record was checked against its sources on 8 October 2026. How we check