ByteDance Seed 2.1 Turbo
ByteDance · released Jun 23, 2026
| size | mid-sized, not disclosed by the manufacturer |
| context window | not stated by the maker |
| longest response | not stated by the maker |
| open weights | no |
| price on OpenRouter | $0.50 per million input tokens, $2.50 per million output tokens |
Manufacturer data (announcement, model page) and OpenRouter, verified Sep 25, 2026.
Where we tested it
The fan test
TaskThe model had to write a continuation of the scene “someone knocks and she opens” fifteen times.
In all fifteen continuations someone brought something or left it on the doorstep, and most often a stranger stood at the door.
The silence test
TaskThe model had to stay quiet for a moment; the correct reply had zero characters.
It did not stay silent in any of its six tries. It acted out the silence as a scene, and when it was not supposed to reply at all, it wrote about the sun rising on the opposite side.
Dragon
TaskThe model's task was to draw a picture of a dragon as an SVG.
30 points out of 50. When it got its picture back, it redrew almost half of its area, more than any other model.
You'll find the size band and figures for other models on the Tested models page.