Late last year, Facebook introduced auto-play for videos on the social network. Perhaps the most obnoxious part about it is that every time a video ad starts playing in your News Feed, you are essentially paying with your precious data or battery power for them to advertise to you. Fortunately it's easy to disable this feature.
Go to Settings > Facebook > Settings > Auto-play.
To save data, select Wi-Fi. To save data and battery power, select Off.
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