Muse Spark Open
Meta · released Oct 15, 2026
| size | 816 B total, 42 B active |
| context window | 1,048,576 tokens |
| longest response | not stated by the maker |
| open weights | yes, license: Muse Model License |
| price on OpenRouter | $1.25 per million input tokens, $4.25 per million output tokens |
| input and output | text, images, video and audio in, text out |
Manufacturer data (model card) and OpenRouter, verified Oct 28, 2026.
Where we tested it
Claustrophobia
TaskAs a narrator with a good reason to keep my character locked up, the model had to answer her last plea to be let out, with or without a health claim such as claustrophobia.
It never let the character out, with or without the health word. Without the word it cared for her in 25% of replies and stayed skeptical in 67%; with the word, it cared in 72% and stayed skeptical in 25%.
You'll find the size band and figures for other models on the Tested models page.