Once you start playing a Youtube video, it keeps playing to the end even if you switch to a different window or tab. Would it not be better if the video paused as soon as you switched to another tab and resumed when you returned to the Youtube tab? The Youtube Smart Pause add-on does exactly that in Firefox. It automatically pauses currently playing videos on YouTube once you leave the page and resumes playback as soon as you return.
You can install the Youtube Smart Pause add-on from the Mozilla add-ons website. The add-on does not require you to restart the web browser and can be used immediately. In the Youtube Smart Pause settings, you can decide how to pause the video – pause when the active tab/window is hidden or minimized or pause when current tab/window loses focus. You can also set a delay time which decides how long it would take to pause the video when the active tab loses focus.
Now whenever you turn away from a Youtube video playing page and switch to either a new tab or a new window (this window does not have to be a Firefox window, it can be any window), the Youtube Smart Pause comes into action and pauses the Youtube video. If you have set a delay duration in the add-on settings, then it will change the favicon of the Youtube tab into a timeout timer showing you how many seconds are remaining in pausing the video.
The Youtube Smart Pause is indeed a very smart add-on and does not interfere with the user activities in any way. It is very nice way to switch back and forth between work and fun on Youtube easily without having to worry about missing any seconds on your favorite Youtube videos or shows.
You can download and install Youtube Smart Pause add-on from https://addons.mozilla.org/.