Other StepFun: Step 3.5 Flash

Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....

ProviderPlanEst. / monthIncludedSource date
Otherstandard$0.50—2026-09-18