After making Task Manager available for Firefox browser at about:performance, today Mozilla has added Process Manager at about:processes page in Nightly version to give information about Firefox processes running with details like memory and CPU they’re utilizing.
While the about:performance reveals information about tabs and add-ons running in Firefox browser and their energy impact on your system and what memory is consumed by each tab/add-on/browser, the newly made about processes page displays following data about each Firefox process:
- Process ID,
- Name
- Memory (resident)
- Memory (Virtual)
- CPU (User)
- CPU (Kernel)
- Threads.

The page shows the process name by
- GPU
- Web
- Extension
- Prevliagedabout
- Socket
- Browser
As of now, you couldn’t draw much from page and details about page is vague at the moment.
Expect Mozilla to add kill button to end a process in the future, the feature is still a work in progress and will evolve and could be more useful to Firefox users.
To see Process Manager in Firefox in action
1. Launch Firefox Nightly
2. Type about:processes and press enter in the address bar.
Check Meta bug.for more details.
You can see all the Firefox internal pages including about:performance at about:about.
Have you ever used Task Manager available at about:performance page in Firefox till now? What you’re expecting from Mozilla on Firefox Process Manager?
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Mozilla Firefox 66 to use 8 Content Processes by default
Mozilla Firefox 67 to discard tabs to free up memory