SponsorBlock

SponsorBlock is an open-source browser extension and open API that skips sponsor segments in YouTube videos. When a video is opened, the extension checks a shared database for submitted timestamps and automatically skips matching segments using a privacy-preserving query system. Users can submit segment start and end points from the YouTube player or the extension popup, and can upvote or downvote segments after skipping.

Beyond sponsor segments, the extension can skip intros, outros, and subscribe reminders, and jump to highlights. Submissions are grouped by overlapping segments, with a weighted random distribution used to select which segment is sent to users, and submissions below a negative vote threshold are ignored. The source code is open, the database can be downloaded, and the public API is documented. The project is intended for YouTube viewers who want to skip known segments, and it is designed to work alongside YouTube Premium and uBlock Origin.