Step-5

Step-5 is Stepfun’s large flagship AI model, designed to work with both text and visual inputs across complex technical projects. Rather than focusing primarily on short conversations, it is built for practical, multi-step engineering and research tasks. For example, users can provide a photo of a bedroom and have the model create an interactive 3D room-planning tool, or assign it to run automated optimization processes on high-performance GPUs over the course of a full day. It can also support large-scale information gathering and organization, such as collecting data from hundreds of online sources to build climate datasets covering thousands of locations.

The model is primarily aimed at software developers, data analysts, and finance professionals working on tasks such as automated problem-solving, code refactoring, and verifiable financial valuation models. Stepfun moved directly from Step-3.7-Flash to Step-5 without releasing a separate Step 4 generation, placing greater emphasis on long-running autonomous execution and the coordinated use of multiple tools than on everyday chat interactions. For the most demanding long-duration tasks, however, frontier models such as Claude Opus 5 may still offer advantages in some areas.