<p>StepFun has released Step 5 Preview as open weights. FP8 and BF16 checkpoints are live on Hugging Face and ModelScope. Step 5 Preview is a sparse Mixture-of-Experts model from StepFun built for long-horizon agentic work. It has 600B total parameters, 27B active per token and up to 1M tokens of context. For developers, this is [&#8230;]</p>
<p>The post <a href="https://www.marktechpost.com/2026/10/16/stepfun-releases-step-5-preview-open-weights-600b-moe-27b-active-1m-context/">StepFun Releases Step 5 Preview Open Weights: 600B MoE, 27B Active, 1M Context</a> appeared first on <a href="https://www.marktechpost.com">MarkTechPost</a>.</p>