This Firefox extension let you add subtitles to any <video> element.
How to use - Open the extension menu by clicking the toolbar icon. - Choose a video element in the list. - Choose a subtitle file with the file picker or upload from a URL.
Features - Supports .srt and WebVTT files. - Customize subtitles color, font and size. - Adjust subtitle delay. - Switch the video to fullscreen with the "Make video fullscreen" button to keep the subtitles in fullscreen mode. - This extension doesn't work with videos inside an iframe, you must first right click the video then select "This Frame" > "Open Frame in New Tab"
Permissions This extension requires the "Access your data for all websites" permission to be able to upload subtitles from any URL.
