Step 5 Preview

Chat Completions

step-5-preview

StepFun|Created Oct 17, 2026|1.0M context

Chat Completions

Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional knowledge work, with particular strength in finance.

Overview Specifications Activity Performance Uptime Examples API Reference

Compare

Uptime

Reliability over the last 7 days

Not enough uptime data to display a chart