AI models by StepFun 3
The full list of AI models from StepFun, best rated first.
Step 5 Preview
StepFun's Step 5 preview model, listed on API aggregators in October 2026
StepFun · Reasoning · Paid
Step-2
StepFun's trillion-parameter reasoning model
StepFun · Reasoning · Freemium
Step-1
StepFun's earlier flagship model that preceded Step-2
StepFun · Language · Freemium