Well I know 1 way but that is to install 2 Extensions : https://addons.mozilla.org/en-US/firefox/addon/disable-autoplay/ HTML5 Wow was I wrong, 438 extensions https://addons.mozilla.org/en-US/firefox/search/?platform=windows&q=stop+auto+play&type=extension Can also try this : https://addons.mozilla.org/en-US/firefox/addon/flashblock/ Blocks Flash so it won't get in your way, but if you want to see it, just click on it or Type copy/paste about:config in the address bar then <enter> . If a warning screen comes up, press the Be Careful button. At the top of the screen is a search bar. Copy/paste into the search at the top of about:config page media.autoplay.enabled = true double click to change it to false The quirks: When Firefox pauses an auto-played video, it may not change the pause button back into a play button. So on those sites, when you do want to start the video, you have to click twice. On sites with GIFV media, there usually are not any visible player controls. You need to right-click the video player area and choose Show Controls. Then you can click the play button. Note : Firefox 57 Quantum release date Nov 14th https://www.mozilla.org/en-US/firefox/quantum/ Note : Legacy Extensions will be disabled and or removed. Please let us know if this solved your issue or if need further assistance.