Stepfun Step 5 Preview (LLM): On AA Pareto frontier (artificialanalysis.ai)

StepFun has unveiled the Step 5 Preview, a proprietary large language model (LLM) set to enhance AI capabilities significantly upon its release in September 2026. This model stands out with a comprehensive context window of 1 million tokens and supports both text and image inputs while delivering text outputs. Achieving a score of 44 on the Artificial Analysis Intelligence Index, Step 5 Preview surpasses the median score of 25, marking it as a prominent contender in the reasoning model category, particularly in its pricing tier. It offers competitive pricing at $1.00 per 1M input tokens and $2.70 per 1M output tokens, making it an attractive option for developers and enterprises looking to leverage advanced AI solutions. The significance of Step 5 Preview lies in its robust intelligence and multimodal capabilities, allowing it to handle complex reasoning tasks and support a wide range of applications. With 600 billion parameters and a performance evaluation generating 160 million tokens during assessments, the model demonstrates exceptional verbosity and processing power. This positions Step 5 Preview not only as a tool for general-purpose applications but also as a viable solution for complex domains like legal work, visual reasoning, and professional document analysis. Its release could pave the way for advancements in AI applications across various industries, elevating user experience and task efficiency.