by Paul Arnote (parnote)
It's happened to us all. We're cruising along using Firefox, have multiple tabs opened up, and then things slow to a crawl. Or, we install a new extension/add-on and find things running slower than normal. It is tempting to just close out Firefox and start over, but there is another choice that may be better.
Firefox has a built in task manager. It will show you exactly how much memory is being consumed by which tabs and which extensions, as well as its energy impact (or CPU cycles ... the higher the CPU cycles, the greater the energy impact). The latter is important to laptop users to help maximize battery life. To access it, you can click on the three line hamburger menu, then select "More ..." from that menu, and select "Task Manager" from the options. Alternatively, you can enter about:performance on Firefox's URL bar.
The task manager first made its debut in Firefox 64 last December.
If it's a tab that's slowing things down, position your mouse over the line that lists the tab that's slowing things down, as evidenced by the amount of memory and energy impact it shows. At the far right side of the window will be a large "X." Click on the "X" to close out that tab.
However, if it's an extension or add-on that's slowing things down, you can position your mouse over the item that's slowing things down. At the far right side of the window will be an arrow. Click on it to open up the Add-on Manager window, where you can disable or uninstall the offending extension or add-on.
If you work like I do, and you have many tabs opened up at any given time, the Firefox Task Manager is an important tool in your arsenal. As I'm writing this article, I have 12 tabs opened up, and have had as many as 20 tabs opened at various times. The tool makes it easy to find memory and energy hogs, and helps dispatch them to the digital netherworld. It sure beats just trying to guess which tabs and extensions/add-ons are guilty of causing the slowdown.