If you are the type of person who opens several tabs at once and reads them one by one much later, then you need this browser user script.
Many news sites have autoplay videos on all their pages. This script will automatically pause them. You can play them manually. It also mutes the videos. If the videos use custom controls, then they may not realize that the videos has been muted. You may have to click on the play and mute buttons more than once to get them working as intended.
This script, by default, does not work on YouTube pages but I have a more powerful YouTube version at https://vsubhash.wordpress.com/2019/03/10/youtube-ad-blocker-and-annoyances-remover-greasemonkey-script-updated
This browser user js is also available at