StepFun
2 models built · 1 served
StepFun (Shanghai Jieyue Xingchen Intelligent Technology Co., Ltd) is a Shanghai lab founded in 2023, known for its Step series of large multimodal models. On OpenKey the lineup is small — two models — but both push large context windows and multimodal input. Step 3.5 Flash is text-only, while Step 3.7 Flash steps up to text, image, and video input, reflecting StepFun's focus on multimodal reasoning rather than a broad general-purpose catalog. Neither model is free. If you need a lab with deep multimodal input handling at low per-token cost, StepFun is worth a look; if you need a huge model roster or free tiers, look elsewhere on OpenKey.
Lineup
With only two models, the choice comes down to modality and budget. Step 3.5 Flash ($0.10/$0.30 per 1M input/output tokens, 262,144 context) is the cheaper, text-only option — use it for straightforward text tasks where you don't need image or video input. Step 3.7 Flash ($0.20/$1.15 per 1M tokens, 256,000 context) costs more, especially on output, but adds image and video understanding on top of text. Pick 3.7 Flash when your task involves visual or video input; otherwise 3.5 Flash is the more economical default.
- Step 3.7 FlashMay 28, 2026 256K $0.206 $1.18 ctx 256K · in $0.206 · out $1.18
- Step 3.5 FlashJan 29, 2026 262K $0.103 $0.309 ctx 262K · in $0.103 · out $0.309
Prices per 1M tokens, flat 3% fee included.
Models StepFun serves
Beyond its own models, StepFun hosts 1 model in the OpenKey catalog. Prices are StepFun’s own list price per 1M input tokens, before our fee.
| Model | Built by | Context | Input /M |
|---|---|---|---|
| Step 3.7 Flash | StepFun | 256K | $0.200 |
From the OpenRouter catalog, Jul 28, 2026. All providers
Questions
- What does StepFun pricing look like on OpenKey?
- StepFun has two models. Step 3.5 Flash runs $0.10 input / $0.30 output per 1M tokens (provider price × 1.03 = $0.103 / $0.309 on OpenKey). Step 3.7 Flash runs $0.20 input / $1.15 output per 1M tokens ($0.206 / $1.1845 on OpenKey after the 3% fee). Neither model is free.
- Which StepFun model should I use?
- Step 3.5 Flash is the cheaper, text-only choice with a 262,144-token context window — good for general text work. Step 3.7 Flash costs more but handles text, image, and video input with a 256,000-token context window, and is the newer of the two (released 2026-05-28). Choose based on whether you need multimodal input.
- Does StepFun offer any free models?
- No. Both StepFun models on OpenKey — Step 3.5 Flash and Step 3.7 Flash — are paid, with no free tier currently listed.