by Stepfun

StepFun: Step 5 Preview.

multimodal closed 1M ctx
Cheapest input
$1.0/M
on OpenRouter
Cheapest output
$2.7/M
on OpenRouter
Hosted equiv.
~$0.97/hr
@ 100 tok/s on OpenRouter

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...

Hosted API only

No self-host path — closed weights.

StepFun: Step 5 Preview's weights aren't published. Use it via the access providers below.

Where to use it

Cheapest hosted endpoints.

Provider Access $/M in $/M out
OpenRouter api aggregator $1.0 $2.7 Launch ↗
FAQ

Frequently asked.

How do I run StepFun: Step 5 Preview?
StepFun: Step 5 Preview is a closed-source API model. The cheapest way to access it is through the API providers listed on this page (direct API, aggregators, and hosted chat UIs).
Where can I access StepFun: Step 5 Preview?
StepFun: Step 5 Preview is available via OpenRouter. Each access option lists its own pricing (per million tokens or hourly hosting).
How much does it cost to run StepFun: Step 5 Preview?
API pricing starts at $1.0/M input tokens and $2.7/M output tokens. Self-hosting cost depends on the GPU you rent — see the Run It Yourself tab.
Is StepFun: Step 5 Preview open-source or proprietary?
StepFun: Step 5 Preview is a proprietary model from Stepfun. Access is API-only — there are no public weights to download.