If you don’t like auto-playing videos, you can disable them on Safari. Go to Safari preferences, open the Websites tab, and select Auto-Play in the left pane. Now you can either check each website’s preferences in the right pane, or enable a global ban across all websites.
Click the drop-down menu next to each website’s name and select Never Auto-Play to stop all videos from playing on their own. Alternatively, you can select Stop Media With Sound to allow videos to play, but on mute.
For those who hate auto-playing videos with a passion, the best course of action is to disable them across all sites. To do this, click the drop-down menu next to When visiting other websites, which is located below the right pane in the Websites tab of the preferences window. There, you can select Never Auto-Play.