From Firefox 64, the browser will have its own task manager. With the tool, that replaces the hard to find about:performance tab, it's possible to see how many resources a website uses. The tool also reveals more detail on the energy consumption of a website.
(How the task manager will look in Firefox 65 - Credits Sören Hentzschel)
With the new task manager, the Firefox developers hope to make it clearer and easier to understand how many resources a website consumes. It will reside in the main menu under “Other” but can also be accessed from the info icon near the website URL on the address bar. The Firefox task manager replaces the about:performance tab. On this tab it's possible to see some performance info on a website, but the Mozilla developers found it too hard to find and too difficult to understand.
The task manager not just better presents the data, but also adds new information, such as the energy consumed by a website. This is represented in categories such as e.g. Low, Medium or High. Also the used resources by extensions can be tracked from the task manager.
Mozilla will first introduce a basic version of the task manager in Firefox 64, which is currently in beta, but should be released on the 11th of December of this year. With the release of Firefox 65 additional enhancements should be added such as a column that shows the memory usage of web pages and extensions. In addition, the energy consumption should be better visually presented.
Besides presenting information, the task manager also makes it possible to perform several actions. It allows users to close tabs, deactivate and uninstall extensions, and pause Javascript execution for a specific tab.
