Open YouTube
Start playing a video
Find the Autoplay toggle on the video player
Turn the Autoplay toggle off
On mobile, tap your profile picture
Tap Settings
Tap Autoplay
Turn Autoplay off
On desktop, click the Autoplay toggle on the right side of the player
Switch it off
In the YouTube app, go to Settings
Open Autoplay
Disable Autoplay on this device
If using embedded videos, pause or disable autoplay in the embed settings if available