◆ Enable “Data Saver” mode
Tap your profile picture in the YouTube app → Go to Settings → Video quality preferences → Under Mobile networks, select Data saver.

◆ Adjust “Video Quality Preferences”
Open the YouTube app → Tap your profile picture → Settings → Video quality preferences → For Mobile networks, choose Data saver (e.g., 480p or lower).

◆ Turn off “Autoplay next video”
Tap your profile picture → Settings → Playback → Toggle off Autoplay next video.
This prevents continuous playback in case you fall asleep or forget to stop the video.

◆ Limit video preloading while browsing your feed
Tap your profile picture → Settings → Playback → Set Play videos in feeds to Off or Wi-Fi only.

◆ Turn off mobile data usage for the YouTube app
For iPhone:
Go to Settings → Mobile Data → Find YouTube → Toggle off to disable mobile data usage.

For Android:
Go to Settings → Apps → YouTube → Mobile data & Wi-Fi → Turn off Allow background data usage.