← All models
stepfun
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. It is a reasoning model that is incredibly speed efficient even at long contexts.
262,144 context
Modalities:text->text
Released:1/29/2026
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. It is a reasoning model that is incredibly speed efficient even at long contexts.
Weekly tokens
1.1B
Tokens generated this week (network-wide)
Usage by period
Today207.7M tokens
This week1.5B tokens
This month8.1B tokens
Trending1.5B tokens