step-5-preview open weights and deployment

Status: Unavailable. StepFun had not published weights as of 2026-09-24. Its announcement says the model will be released with open weights on October 15, and the ModelScope pre-release page lists 2026-10-15; the licence and recommended runtime are not yet published. Step-5-Preview repositories under other accounts are not official.

Need to self-host? Open-weight alternatives: deepseek-flash, glm-5.3-flash.

License
Not yet published
Hardware note
Not applicable until official weights are released
Recommended runtime
ChinaAPI or the StepFun API
Verified date
2026-09-24

Published model card

Parameter count
600B total, 27B active per token (sparse MoE)
Context window
1M tokens
Maximum output
64k tokens
Input/output modalities
Text, image and video input; text output

Official sources