Overview
StepFun (阶跃星辰) is a leading Chinese AI lab competing on frontier MoE models, agentic coding, and aggressive API pricing.
Recent Developments
- 2026-09-20: step-5-preview flagship — 600B sparse MoE, 27B active/token, 1M context, vision input; API live; open weights planned Oct 15, 2026 (2026-09-20-stepfun-step-5-preview)
- Artificial Analysis Intelligence Index score: 44 (median comparable: 25); API pricing 2.70 per M input/output tokens (2026-09-20-stepfun-step5-artificial-analysis)
Benchmark scores and capability claims are vendor/Artificial Analysis reported — independent replication pending.