Open-Source StepFun Models

Quick answer · Updated June 2026

The best open-weight StepFun model is Step 3.7 Flash (42.6 intelligence) — downloadable from Hugging Face and self-hostable. Step 3.5 Flash (37.8) is next.

42.6Intelligence

92 t/sSpeed

$0.200Input /M

256KContext

The best open-weight AI models — downloadable from Hugging Face and self-hostable — ranked by intelligence. Open-source alternatives to proprietary frontier models.

1S
step-3.7-flash
ReasoningToolsJSON+142.6 intel · $0.200/M · 92 t/s
42.6
Intelligence
2S
step-3.5-flash
ReasoningToolsJSON37.8 intel · $0.090/M · 47 t/s
37.8
Intelligence

Frequently asked

What is the best open-source StepFun model?

The best open-weight StepFun model is Step 3.7 Flash (42.6 intelligence) — downloadable from Hugging Face and self-hostable. Step 3.5 Flash (37.8) is next.

What's a good alternative to Step 3.7 Flash?

Step 3.5 Flash (37.8) is the closest alternative on this metric. See the full ranking above for the tradeoffs.

How many StepFun models are there?

modelgrep tracks 2 StepFun models with live benchmarks, speed, latency and per-provider pricing, led on intelligence by Step 3.7 Flash. 2 of them qualify for this ranking.

More StepFun rankings

StepFun: Smartest LLMs StepFun: Best LLMs for Coding StepFun: Best LLMs for Design & Frontend StepFun: Fastest LLMs StepFun: Lowest-Latency LLMs StepFun: Cheapest LLMs StepFun: Best Free LLMs StepFun: Best Reasoning LLMs StepFun: Best Vision LLMs StepFun: Best LLMs for Agents StepFun: Longest-Context LLMs

All rankings

Small & Fast LLMs Smartest LLMs Best LLMs for Coding Best LLMs for Design & Frontend Fastest LLMs Lowest-Latency LLMs Cheapest LLMs Best Free LLMs Best Reasoning LLMs Best Vision LLMs Best LLMs for Agents Longest-Context LLMs