Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...
stepfun/step-5-previewStep 5 Preview is an API model from stepfun, released on Oct 8, 2026, with a context window of 1,048,576 tokens, pricing of $1 per million input tokens and $2.7 per million output tokens. It accepts image, text, video input and produces text output.
At listed prices, a request with 10,000 input tokens and 1,000 output tokens costs about $0.013.
Specs are sourced from OpenRouter and were last checked on Nov 3, 2026. Always confirm current pricing and limits with the provider before production use.
Step 5 Preview supports a context window of 1,048,576 tokens.
Step 5 Preview is listed at $1 per million input tokens and $2.7 per million output tokens on OpenRouter.
Step 5 Preview was published on Oct 8, 2026.
Step 5 Preview accepts image, text, video input and produces text output.