Notice YouTooltip is now using Manifest V3. In Manifest V3, you will have to manually grant YouTooltip permission to run on webpages. You may either grant access to all sites, only individual sites, or only when clicking on the toolbar button. Versions using Manifest V2 (1.4.0 and earlier) have such permissions granted on install, and you do not need to do anything. Manifest V3 is only supported on Firefox 109 and later. If you are using an older version of Firefox then you will need to install an older YouTooltip version from the version history page. Features - Auto and hover operation modes. - Supported API's: Google, Invidious, and Piped. - Display mode: Tooltip, custom tooltip, or notification. - Field and formatting options. - Popup. Permissions Optional - Access your data for all websites: For automatically scanning each page for links to YouTube videos and playlists without user interaction. - Display notifications to you: For notification display mode, instead of displaying youtube info as tooltips. Other notes The default API key(s) that YouTooltip uses are my own, and I have the right to disable them at any time for any reason. In addition, Google may also disable them at any time for any reason. You may choose to provide your own API key, but you are responsible for its use. Credits Forked from YoutubeTooltip (since removed from AMO) written by Firefox user 14151097.