Auto-playing videos are a huge annoyance as they distract attention, gobble up bandwidth and monthly data usage and they waste CPU cycles and battery.
Third-party extensions such as AdBlock Plus and FlashBlock can go a small way to disabling auto-playing videos, but the latest HTML5 auto play videos cannot be disabled this way. After a few years of nagging and user feedback, both Google and Mozilla have introduced a native method for disabling autoplay videos in HTML5.
Disable Autoplay HTML5 Videos in Firefox
Firefox ships with a hidden option called
media.autoplay.enabled which you can set to false on the about:config page. While it does prevent some videos from being played automatically, it won't prevent all HTML5 video contents as there are ways to bypass the restriction.
To access this feature navigate to about:config in your Firefox address bar.
In the next page, acknowledge the risk that dragons pose:
Now search for the setting
media.autoplay.enabled and set the value to false by double clicking it.
You can reverse that at any time by double-clicking again, or by right-clicking on the preference and selecting the reset option from the context menu.
Disable Autoplay HTML5 Videos in Chrome
Chrome features an almost identical hidden configuration option. To block autoplay videos in Chrome simply follow these steps:
Navigate to chrome://flags/#autoplay-policy in the Chrome address bar.
The Autoplay policy should be set to Default when you load the page. You'll need to set the drop box option box to Document user activation is required so that you have to approve any video to play on a website.
Lastly, you'll need to click on the blue Relaunch Now button found at the bottom of the page. This will restart the Chrome browser and activate the change.
You can reverse this change by selecting default from the drop-down list.