Recently we reported Mozilla is reviving the automatic Tab unloading feature with Firefox 93. The feature unloads tabs when system memory is low. It aims to improve Firefox memory usage and fix out memory crashes. We also told you, the organization is planning to prepare chrome://discards equivalent for Firefox tab unloading, well, about:unloads page is now ready in Firefox 94.
Firefox about:unloads page
about:unloads page when visited in the Firefox address bar, gives a basic idea of how Firefox prioritizes tabs and which tab gets unloaded if tab unloading becomes active.
The page also offers unload button to discard a tab.
Note: The highest priority tab will be backgrounded first.
When a user clicks on a discarded tab, it will reload again.
The table contains 7 columns: Priority, Host, Last Accessed, Base weight, Second weight, Memory, and Process IDs.
When the feature triggers, tab(s) based on priority gets inactive, resources will be freed, thus system memory comes back to normal and Firefox becomes smooth and responsive again.
Process IDs will appear as bold when they are hosting in the tabs top frame, displayed as italic when the process is shared between different tabs.
This may well resemble the Task Manager or about:performance page in Firefox. It shows tab title, type, and Energy impact and memory tabs are consuming. To open TM in Firefox, click on menu > more tools, select Task Manager.
The difference between about:unloads and about:performance is former allows you to discard tabs on demand, where the latter lets you kill tabs when you notice they’re hogging system memory and CPU.
Time will tell, how useful the feature is when it makes into release. Users have already seen this. The about:unloads let you visualize tabs that going to unload next and offer a trigger button to manually unload tabs.
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