If you are someone who keeps dozens of tabs open simultaneously, you may have noticed that when you return to a tab you haven’t looked at in a few hours, the page goes blank and completely reloads itself. This is because Mozilla Firefox includes an automatic memory management feature that “discards” (or unloads) background tabs when your computer starts running low on RAM. While this prevents your system from crashing, it can be infuriating if you were halfway through filling out a long web form or reading an article offline, as reloading the page destroys your progress. You can stop Firefox from killing your idle tabs.
How to Disable Automatic Tab Discarding
This setting is hidden deep within Firefox’s advanced configuration page, as it can significantly impact system memory if abused.
- Open the Mozilla Firefox browser.
- Click on the main URL address bar at the top of the window.
- Type about:config and press Enter.
- A warning page will appear stating “Proceed with Caution.” Click the Accept the Risk and Continue button.
- At the top of the configuration page, you will see a “Search preference name” box.
- Type the following exactly: browser.tabs.unloadOnLowMemory
- The preference will appear below the search bar. You will see its current value is set to true.
- To the far right of the preference name, click the small button with two opposite-facing arrows (the Toggle button).
- The value will instantly change from true to false.
Firefox will no longer suspend your background tabs, regardless of how much memory they consume. Be aware that if you open too many heavy websites simultaneously on a machine with limited RAM, your entire computer may slow down significantly.