中EN Submit a tool

Step 3.5 Flash

Rank #174 stepfun

stepfun/step-3.5-flash

Usage data date 2026-07-26 · updated daily

Leaderboard Back to home

Usage and specs

Daily rank#174
Daily tokens3.9B
Daily requests248.8K
Daily change +92.0%
Context window256K
Released

What is 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.

Step 3.5 Flash capabilities

Input: Text   Output: Text

Reasoning output Reasoning Tool choice Tool use

Step 3.5 Flash API pricing

Input · per 1M tokens$0.10
Output · per 1M tokens$0.30

List prices in USD; see each provider’s site for current terms.