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Step 5 PreviewOPEN
Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters).
Prices update automatically — checked daily against provider list prices.
- $1.43 per 1M tokens, assuming 3 input for 1 output the convention used by Artificial Analysis
- cheaper than 8% of the 202 open-weight models tracked here
- 3 of 3 Stepfun models tracked here, from cheapest
Benchmarks & performance
Independent benchmark scores for Step 5 Preview, measured by Artificial Analysis. Higher is better.
For the same budget, Step 5 Preview delivers 4.3 times more capability. Open weights also mean you can self-host it and pay nothing per token.
Models at this level cost $2.25 per 1M tokens (median of 16) — this one costs $1.43.
Cheaper and better on this index: MiMo-V2.6-Pro · DeepSeek V4.1 Flash 1017 · GLM 5.3 and 1 more
About this model
Step 5 Preview is an open-weight AI model by Stepfun. You can download and self-host it for free; the prices below are hosted-API list prices, tracked daily, for when you prefer convenience over self-hosting.
Frequently asked questions
What is Step 5 Preview?
Step 5 Preview is an AI language model from Stepfun. It is open-weight: you can download it and run it on your own hardware, for free. It scores 43.7 on the Artificial Analysis intelligence index.
Is Step 5 Preview free?
The weights are free and open — you can self-host Step 5 Preview and pay nothing per token. If you prefer a hosted API, list prices are $1 per million input tokens and $2.7 per million output tokens.
What is Step 5 Preview good at?
Independent benchmarks from Artificial Analysis give it Humanity's Last Exam 46.5%, Long Context Reasoning 88.3%, SciCode 58.9%.
How fast is Step 5 Preview?
It generates about 193.3 tokens per second, with a median 1.35s delay before the first token. Measured independently by Artificial Analysis.
Can I self-host Step 5 Preview?
Yes. Step 5 Preview has open weights, so you can download it and run it on your own GPU or server with tools like Ollama, vLLM or llama.cpp — with no per-token cost.