Information covers the Mozilla Firefox web online window on Windows, macOS, and Linux computers.
Firefox’s about:memory page lets you troubleshoot memory issues.
Typeabout.memoryinto the Firefox search bar to generate memory reports and minimize memory usage.
How to Update Firefox
Updating Firefoxis always a good idea.
You’ll install new security patches and take advantage of any performance enhancements.
If there were a bug causing memory leaks, updating Firefox could eliminate the issue.
Select theMenuicon (three horizontal lines) in the upper-right corner.
SelectOptionson the drop-down menu.
(On a Mac, selectPreferences.)
ThePreferencespage opens with theGeneralcategory loaded by default.
Scroll down toFirefox Updates.
Firefox uses background services and updates search engines by default.
Restart Firefox if needed.
This process requires loading Firefox in Safe Mode.
Typeabout:supportin the address bar and pressEnterorReturn.
SelectTroubleshoot Modeto restart Firefox without any extensions or themes.
Use Firefox as usual while checking your memory and CPU percentage.
If memory or CPU usage is still high, then extensions and themes aren’t the problem.
If the numbers remain low, disable themes and extensions.
How to Disable Firefox Extensions
Disable all extensions to see if the memory issue clears.
If it does, re-enable each extension one at a time to determine the offending, memory-gulping addition.
SelectAdd-onsfrom the drop-down menu.
SelectExtensionsin the menu on the left.
Select thethree-dot iconnext to an extension.
SelectDisableon the drop-down menu.
Repeat this process for each extension.
Revert to the default theme and see if system performance improves.
SelectThemesin the menu on the left.
UnderDisabled, select thethree-dot buttonnext toDefault.
SelectEnableon the popup menu.
You’ve restored the default theme.
But hardware acceleration may cause problems, depending on your configuration.
Turn off hardware acceleration and see if this improves system performance.
SelectOptionsfrom the drop-down menu.
(On a Mac, select Preferences.)
ThePreferences pageopens with theGeneralcategory loaded by default.
By default, Firefox enables theUse recommended performance settingsoption.
Uncheck theUse hardware acceleration when availablefeature.
See if your system performance improves.
Here you’re free to also change the content process limit.
A higher number means better performance when running multiple tabs at the cost of additional memory.
Eight is the default setting, but if you’re experiencing memory issues, try lowering the process number.
Use the Built-in Memory Tool
Firefox provides a built-in tool to show memory reports and save logs.
It allows you to clear memory and minimize memory usage.
Typeabout:memoryin the address bar and pressEnterorReturn.
Locate theFree memorypanel and selectMinimize memory usage.
Optionally, you’re free to select theGC(garbage collection) andCC(cycle collection) buttons.
This extension suspends inactive tabs after a specific period of time.
Here’s how to install Auto Tab Discard.
Head to theAuto Tab Discardlisting on the Mozilla Firefox Add-ons page.
SelectAddin the in-web app popup window that appears.
ClickOkay, Got Itto confirm the add-on management instructions.
You’ll now see a power button icon located next to the Firefox menu button.
TheOptionssection provides parameters for discarding options, conditions, and exceptions.
Reduce Firefox Session History
One possible memory hog is yourFirefox session history.
The maximum per-session history limit is 50, meaning Firefox stores 50 webpage addresses in memory.
Typeabout:configin the address bar and pressEnterorReturn.
Typebrowser.sessionhistory.max_entriesin the search field and pressEnterorReturn.
Double-poke the current value (50).
Enter a lower number in the popup window’s text field.
Delete the content-prefs.sqlite File
The file storing individual website data may be corrupt.
Delete the content-prefs.sqlite file and Firefox will create another once it restarts.
This may solve your memory issues.
Under theApplication Basics, next toProfile Folder, selectShow in Finder.
A window will open that contains your profile folder.
In your profile folder, delete the filecontent-prefs.sqlite.
It will be recreated next time you open Firefox.
SelectRefresh Firefoxin the confirmation popup.
