Examples: 4K YouTube to MP3 (Free version), YT-DLP (command line), JDownloader 2.
Best for: One-click downloading.
While many extensions have died, "Video Downloader Plus" remains updated. Unlike fake downloaders, this one appears as a blue button next to the URL bar. mp3 downloader youtube firefox free
If you are a developer or power user, yt-dlp is the ultimate back-end MP3 downloader. You run it in Terminal (Command Prompt), pass it a YouTube URL, and it outputs a perfect MP3.
This is the only solution that has worked consistently for five years and will likely work for five more. Examples: 4K YouTube to MP3 (Free version) ,
While technically not a "Firefox extension," the 4K Video Downloader is the gold standard for users serious about audio quality. It has a "Smart Mode" that captures links from your Firefox clipboard automatically.
Most tech journalists agree: pairing Firefox with a lightweight external downloader is safer than injecting code into the browser. This is the only solution that has worked
Best for: Power users who download playlists.
Technically, this is not a Firefox add-on, but a standalone program. However, it integrates beautifully with Firefox via copy-paste.
SaveFrom.net was once the king. Their Firefox helper extension still exists, but recent versions bundle adware. Only use the web version (en.savefrom.net) inside a private Firefox window. Never install their software.