Stepzen unveils step5preview, a high-performance AI model with reduced costs

StepZen has launched Step5Preview, its flagship base model, designed for AI programming, software engineering, professional work, and finance. The model enhances real-world Agentic task performance while optimizing the balance between intelligence, cost, and efficiency. It ranks among the top three global open-source models in the Artificial Analysis Intelligence Index (AA Comprehensive Intelligence Index), with a single-task cost that is only 1/8 of Claude Opus5. The model is set to be officially open-sourced on October 15, 2026. Step5Preview employs a sparse MoE architecture, featuring a total parameter count of 600B, with only 27B activated parameters. It supports a 1 million Token context window and natively handles text and visual input. The model has been optimized for complex tasks in software engineering, professional workflows, and finance.