StepFun Releases Step 5 Preview Open Weights: 600B MoE, 27B Active, 1M Context

StepFun released Step 5 Preview as open weights, publishing FP8 and BF16 checkpoints on Hugging Face and ModelScope. The sparse Mixture-of-Experts model has 600B total parameters, 27B active per token and up to 1M tokens of context, and StepFun built it for long-horizon agentic work.

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 … The post StepFun Releases Step 5 Preview Open Weights: 600B MoE, 27B Active, 1M Context https://www.marktechpost.com/2026/10/16/stepfun-releases-step-5-preview-open-weights-600b-moe-27b-active-1m-context/ appeared first on MarkTechPost https://www.marktechpost.com .