If your goal is to listen to music without an internet connection, the official method is the most reliable and highest-quality option. On Mobile (Android & iOS)

: If your Premium subscription expires, you lose access to these offline files.

: Audio is typically streamed and downloaded at 256kbps AAC , which is a high-quality format but technically different from MP3. Step-by-Step: Official Offline Listening

This article explores how the official "offline" feature works and the specific legal scenarios where you can obtain actual MP3s. How Official YouTube Premium "Downloads" Work