StepFun Launches Step 5 Preview: 600B Sparse MoE, 1M Context, Weights Open Oct 15

StepFun introduced Step 5 Preview, a sparse MoE model with ~600 billion total parameters (27 billion active per token), 1 million token context, and support for text and images. The API is already available at $1 per 1 million input tokens and $2.7 per 1 million output tokens, with weights promised to open on October 15.

• 600 billion total parameters, ~27 billion active per token
• 1 million token context, text and image input
• API: $1 per 1M input tokens, $2.7 per 1M output tokens
• Model weights to open on October 15