Step 3.5 Flash

Published

Feb 2, 2026

Step 3.5 Flash is an AI model developed by StepFun (China), first published in February 2026. It works in the language domain, on tasks such as language modeling/generation and question answering.

Epoch AI has no training-compute estimate for this model.

Access: Open weights (unrestricted). Its weights are openly available. Epoch AI rates the confidence of this record as likely.

Full record

Organization: StepFun
Country of organization: China
Domain: Language
Task: Language modeling/generation, Question answering
Model accessibility: Open weights (unrestricted)
Open weights: Yes
Epoch confidence: Likely