Open YouTube
Start playing a video
Tap the Autoplay toggle on the video player to turn it off
On mobile, tap the video, then tap the Autoplay switch
On desktop, use the Autoplay switch in the right-side panel or near the player
In the YouTube app, go to Settings
Tap Autoplay
Turn off Autoplay next video
In YouTube Music, open Settings
Turn off Autoplay
If needed, disable autoplay in your device browser settings or browser extensions