StepFunOpen sourceMateriality 5

StepFun releases open weights for Step 5 Preview model

StepFun has released open weights for its Step 5 Preview model, a 600B parameter model with 27B active parameters and a 1M token context. A technical blog details its 92-layer design, Sparse GQA and long-horizon agent training.

First seen 15 Oct, 09:42 UTC on Pandaily2 sourcesLast update 1h ago

StepFunLaunch · 15 Oct

Step 5 Preview

Frontier-class model launch

1Mcontext

Openweights

What the sources say

Linked, never rewritten. Official means the lab itself.

Official0

No word from StepFun yet.

Press2

Pandaily· 15 Oct, 09:42StepFun Releases Open Weights for Step 5 Preview, Publishes Technical Blog on Its Architecture Pandaily· 16 Oct, 03:06Ascend, MetaX, Biren and Moore Threads Announce Day-0 Support for StepFun's Step 5 Preview

How it unfolded

Every source in the order it appeared. Times in UTC.

15 Oct 09:42Pandaily StepFun Releases Open Weights for Step 5 Preview, Publishes Technical Blog on Its Architecture 16 Oct 03:06Pandaily Ascend, MetaX, Biren and Moore Threads Announce Day-0 Support for StepFun's Step 5 Preview