Model Capability Overview

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.

Combines visual perception with complex reasoning for cross-modal analysis and knowledge-intensive tasks.

An ultra-fast MFA-attention model that delivers strong general-task and coding performance at lower cost.

The production step-2 model with stronger overall quality, feel, and planning ability.

The 8K variant of the step-1 family, tuned for short-context generation, Q&A, and tool-oriented workflows.

The 32K step-1 variant extends the classic family with a larger window for longer conversations and document-heavy tasks.

A reasoning model for image understanding and deep thinking, with strong performance on vision, math, and coding tasks.

The recommended vision model for image and video understanding, with a lighter footprint and faster output.

A strong image-understanding model with text-and-image input and text-only output, positioned above the step-1v series in visual quality.

The 8K member of the step-1v series for short-context image Q&A and visual analysis.

The 32K step-1v variant handles more images and longer histories for vision understanding tasks.

A text-to-image model with strong Chinese-language support and high-resolution output for general image generation.

A new-generation image model focused on more realistic output and stronger Chinese-and-English text rendering.

An image-editing model that modifies and enhances input images based on image-plus-text instructions.

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.

A TTS model focused on emotional expressiveness and controllable style, suitable for multi-emotion voice output and cloning.

A speech-synthesis model optimized for highly human-like output and strong realism in outbound-call 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.

32B-parameter ASR Pro model.

A mature first-generation end-to-end voice model suited to foundational voice interaction and content generation.

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.

Combines visual perception with complex reasoning for cross-modal analysis and knowledge-intensive tasks.

An ultra-fast MFA-attention model that delivers strong general-task and coding performance at lower cost.

The production step-2 model with stronger overall quality, feel, and planning ability.

The 8K variant of the step-1 family, tuned for short-context generation, Q&A, and tool-oriented workflows.

The 32K step-1 variant extends the classic family with a larger window for longer conversations and document-heavy tasks.

A reasoning model for image understanding and deep thinking, with strong performance on vision, math, and coding tasks.

The recommended vision model for image and video understanding, with a lighter footprint and faster output.

A strong image-understanding model with text-and-image input and text-only output, positioned above the step-1v series in visual quality.

The 8K member of the step-1v series for short-context image Q&A and visual analysis.

The 32K step-1v variant handles more images and longer histories for vision understanding tasks.

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.

A TTS model focused on emotional expressiveness and controllable style, suitable for multi-emotion voice output and cloning.

A speech-synthesis model optimized for highly human-like output and strong realism in outbound-call 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.

32B-parameter ASR Pro model.

A mature first-generation end-to-end voice model suited to foundational voice interaction and content generation.