Straight answer, because most pages about this dodge it: downloading YouTube content with third-party rippers violates YouTube’s Terms of Service, and for copyrighted music it is also copyright infringement in most countries. Some jurisdictions have a narrow private-copying exception, but it generally doesn’t cover circumventing a streaming service. The ripper sites themselves are also a practical risk — they’re a well-known vector for malicious ads and bogus downloads.
Legitimate ways to get what you actually want (offline listening):
- YouTube Premium — official offline downloads in the app for everything on the platform, including YouTube Music. This is the direct, sanctioned answer, and if offline listening matters to you regularly it’s the honest recommendation.
- Podcast versions — a large share of talk content on YouTube (interviews, lectures, commentary) is also published as a podcast, where downloading for offline play is an intended feature and completely free. Search the show name in any podcast app first; this solves the problem more often than people expect.
- Creator-provided downloads — many creators offer MP3s on their own site, Bandcamp, or Patreon. If you like their work, this route also pays them.
- Openly licensed music — Free Music Archive, Jamendo, and the YouTube Audio Library provide music that is explicitly free to download and, in many cases, to use in your own videos.
- Your own uploads and Creative Commons videos — YouTube’s own tools let you download your uploads; CC-BY videos permit reuse with attribution (check the licence shown under the video, not just an assumption).
If the content is your own recording or public-domain material, none of the above is an issue — see the separate thread on extracting audio from a video file you already have with FFmpeg: Extract audio from a video (MP4 to MP3) for free — cleanest method?
We’re not going to recommend specific ripper tools — beyond the legal problem, they change domains constantly and the ad networks on them are hostile. If offline listening is the goal, Premium or the podcast feed gets you there without any of it.
What kind of content are you trying to take offline — music, or talks and lectures? For talks there’s almost always a free legitimate feed.