StepFun open-sources Step 5 Preview: 600B sparse MoE with 27B active params, 1M context
CurieuxExplorer · x · 2026-10-16
StepFun has released open weights for Step 5 Preview, with BF16 and FP8 checkpoints live on Hugging Face and ModelScope alongside a technical blog.
- Sparse MoE: 600B total parameters, 27B active per token
- 1M-token context window
- Native text and vision input
- Built for long-horizon agentic work: coding, software engineering, professional knowledge work, and finance
The release brings frontier-class intelligence to the open-weights camp, challenging the closed-model race.
Related event: StepFun Open-Sources Step 5 Preview: 600B-Parameter MoE with 1M Context(17 posts)→
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