Subscribe to YouTube Premium
Open the YouTube app on your iPhone
Start playing the video
Press the Home button or swipe up to leave the app
Keep using Picture-in-Picture if available
Use Safari instead of the YouTube app
Go to youtube.com in Safari
Request the desktop site if needed
Start the video
Switch to another app or lock the screen
Use the YouTube Music app for music playback with Premium
Turn on Picture-in-Picture in iPhone settings if supported
Check that background playback is allowed in YouTube Premium settings
Use a third-party browser that supports background audio
Keep the video playing while the screen is off only if the method supports it