Model Capability Overview

StepFun’s flagship multimodal reasoning model. Building on step-3.5-flash’s high-throughput reasoning and tool calling, it adds native multimodal input — understanding images and videos directly, without an additional vision MCP or auxiliary model. Three reasoning effort levels (low / medium / high) make it a fast and dependable choice for agent, coding, and multimodal workloads.

A flagship reasoning model built for agents. Its reasoning depth rivals leading closed-source models while also delivering ultra-fast responses and stable, reliable tool calling. On top of strong general reasoning, it excels at complex project planning and long-horizon task execution.

The first model to integrate contextual understanding into the full speech generation pipeline. Supports Global Context + Inline Context dual-level control via natural language descriptions for precise emotion and style control. Ideal for audiobooks, drama dubbing, ad narration, and other high-expressiveness scenarios.

StepFun’s new-generation streaming speech recognition model, based on a 4B MTP architecture that balances recognition accuracy with low latency. Supports Chinese and English recognition with ITN text normalization — well suited to realtime captions, voice input, and meeting transcription where both speed and accuracy matter.

StepFun’s flagship multimodal reasoning model. Building on step-3.5-flash’s high-throughput reasoning and tool calling, it adds native multimodal input — understanding images and videos directly, without an additional vision MCP or auxiliary model. Three reasoning effort levels (low / medium / high) make it a fast and dependable choice for agent, coding, and multimodal workloads.

A flagship reasoning model built for agents. Its reasoning depth rivals leading closed-source models while also delivering ultra-fast responses and stable, reliable tool calling. On top of strong general reasoning, it excels at complex project planning and long-horizon task execution.

The first model to integrate contextual understanding into the full speech generation pipeline. Supports Global Context + Inline Context dual-level control via natural language descriptions for precise emotion and style control. Ideal for audiobooks, drama dubbing, ad narration, and other high-expressiveness scenarios.

StepFun’s new-generation streaming speech recognition model, based on a 4B MTP architecture that balances recognition accuracy with low latency. Supports Chinese and English recognition with ITN text normalization — well suited to realtime captions, voice input, and meeting transcription where both speed and accuracy matter.