How to use this addon? (1). Install the Addon (2). Click the cube box in the top right corner and pin this addon (so that the addon is visible in the browser tab) (3). Play any video on youtube, click the addon icon in the top right corner to download. (Available MP4 and MP3) Please play the video on youtube then click the icon in the top right tab to download mp3 or videos. Note: This add-on will direct the user to a downloader website to download the video or mp3 of your choice from youtube. This add-on will direct the user to a downloader website to download the video or mp3 of your choice from youtube. Because converting video to mp3 requires a large FFMPEG server, the downloader website has safe and inoffensive advertisements, these ads are for paying the converter server rental. If you are annoyed with advertisements, then this addon is not suitable for you, look for other addons in mozilla addons that do not have ads. Thank you for understanding.