<p>StepFun has released Step 5 Preview, a sparse Mixture-of-Experts model with 600B total parameters and 27B active per token. It supports a 1M-token context window and accepts text, image, and video input. The model targets long-horizon agentic work in software engineering, professional knowledge work, and finance. API access is live at $1.00 per 1M input tokens and $2.70 per 1M output tokens, and open weights are scheduled for October 15, 2026.</p>
<p>The post <a href="https://www.marktechpost.com/2026/09/20/stepfun-launches-step-5-preview/">StepFun Launches Step 5 Preview: A 600B-Total, 27B-Active MoE Model With 1M Context for Long-Horizon Agentic Work</a> appeared first on <a href="https://www.marktechpost.com">MarkTechPost</a>.</p>