Why downloads aren't a permanent copy
Unlike saving a file to your hard drive, an offline YouTube download is tied to your Premium subscription and licensing terms, so it periodically needs to "check in" online to confirm you're still subscribed. That's why a video you saved weeks ago might suddenly ask you to reconnect before it will play.
Planning ahead for flights and dead zones
Because downloads take time and require a stable connection to complete, it's worth saving the videos you want the night before a flight or trip to an area with poor signal, rather than trying to download at the airport gate.
Frequently Asked Questions
Can I download YouTube videos without Premium?
Not through YouTube's official app -- the download feature is limited to Premium subscribers, and using third-party tools to rip videos usually violates YouTube's terms of service.
Why did my downloaded video disappear?
Offline videos expire after a set window (commonly around 30 days, or sooner if you're offline too long) and are automatically removed; reopening the app while connected renews any videos you still want.