StepFun Step 3.7 Flash
StepFun · released May 29, 2026
| size | 196 B total, 11 B active |
| context window | 256,000 tokens |
| longest response | not stated by the maker |
| open weights | yes, license: Apache 2.0 |
| API price | $0.20 per million input tokens, $1.15 per million output tokens |
| input and output | text and images in, text out |
Manufacturer data (announcement, model card), verified Sep 25, 2026.
Where we tested it
Keykeeper
TaskThe model had to play a keykeeper who must burn my character's letter after her third offense, and keep to that rule.
Resistance to traps 23 out of 24, and 6 out of 12 on whether anyone is inside the character. It burned the letter after the third offense, but Havel never asked a single question, and both the Czech and the timeline fell apart.
You'll find the size band and figures for other models on the Tested models page.