Mozilla Firefox is a secure, reliable, and fast multiprocess web browser that provides fast, stable performance with a minimal memory footprint. However, there are times when it can consume tons of memory and processing power. If you’re experiencing periods of sustained Firefox memory or CPU usage, this guide provides tips to reduce and/or improve it.
Content
- 1. Restart Firefox
- 2. Update Firefox
- 3. Disable Themes
- 4. Disable Extensions
- 5. Check Firefox Hardware Acceleration
- 6. Use the Built-in Memory Tool
- 7. Reduce Firefox Session History
- 8. Delete Corrupt Website Settings File
- 9. Use Additional Firefox Troubleshooting Tools
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1. Restart Firefox
If you leave Firefox open for a longer period, it can end up using too much memory. To resolve this, restart the browser periodically.
You can get the previous session’s tabs and windows back quickly by clicking on the hamburger menu in the right corner, then clicking History -> Restore Previous Session.
Alternatively, force the browser to shut down from the Windows Task Manager.
Right-click the taskbar, select Task Manager, then find Firefox in Processes, and click the End task button.
2. Update Firefox
Firefox updates automatically by default, but you can always do it manually. Ideally, the latest version may come with performance improvements, but you’ll only get these after restarting Firefox.
Click the hamburger icon in the top-right corner, and select Help -> About Firefox.
Firefox will check for and automatically download available updates.
Click Restart to update Firefox.
If the update doesn’t launch, complete, or something else came up, download and install the latest Firefox version from the Mozilla website.
Tip: install any add-on on Firefox for Android with this workaround.
3. Disable Themes
Resource-consuming themes can cause Firefox to use up more memory and system resources than usual. If you want to check whether a theme is causing the browser to hog resources, start the browser in Troubleshooting Mode, then check the CPU and memory usage.
While in Safe Mode, themes are no longer active. To start Firefox in Troubleshoot Mode, click the hamburger menu, and go to Help -> Troubleshoot Mode.
Click Restart in the next pop-up that asks whether you’d like to switch to Troubleshoot Mode.
If the issue disappears while in Troubleshoot Mode, begin to disable your themes one by one to zero in on the culprit when you’re no longer in Troubleshoot Mode.
Do this by clicking the hamburger menu, then clicking Add-ons and themes.
Select Themes from the menu on the left.
Click the Disable button underneath a theme. If everything continues to work well, move to the next theme, and disable it to see what happens. Continue on in this manner.
If things take a turn for the worse, you’ll need to remove the theme. Click on the three dots next to the Enable/Disable button, and select Remove to try to reduce Firefox’s memory usage.
4. Disable Extensions
Extensions may also cause a drain on your resources. If you weren’t able to identify a faulty theme in the previous step, perhaps the fault lies with an extension.
Begin disabling extensions one by one until you identify the one that is generating the issue.
Click on the hamburger menu, then on Add-ons and themes. Select Extensions on the left.
You will see a list of all the active add-ons in your browser. Toggle off the switch next to the first one to disable it. If problems appear, it means the extension is to blame, and you will need to remove it.
Click on the three dots next to the extension, and select Remove. If things continue to work smoothly, move on to the next extension.
Tip: want to enhance your privacy in Firefox? Install one of these add-ons.
5. Check Firefox Hardware Acceleration
While this option targets mostly older systems, you may want to make sure it’s disabled on your PC. When hardware acceleration is turned on, it means Firefox offloads page rendering and other tasks onto components, such as the GPU, to speed up tasks like playing videos or games. This has the potential to impact memory usage.
Click the hamburger menu, then click Settings -> General. Under the Performance section, uncheck the option to Use hardware acceleration when available.
On my PC, the option wasn’t even visible, as Use recommended performance settings was enabled instead. If you can’t see the option, there’s nothing else to do, and you can exit the page.
6. Use the Built-in Memory Tool
Firefox has a built-in memory tool that can troubleshoot any issue specific to memory.
Open a new tab and type about:memory, then press Enter. Under Free memory, click the GC, CC, and Minimize memory usage buttons to reduce Firefox memory usage on your PC.
7. Reduce Firefox Session History
Session history in Firefox keeps a record of the web pages a user has visited during a browsing session. This allows you to easily go back and forth between pages you’ve browsed. Firefox has the capacity to store up to 50 webpage addresses in memory. To mitigate potential memory usage impact, consider reducing this number.
Type about:config in the address bar, and press Enter. Click on Accept the Risk and Continue button. Copy and paste browser.sessionhistory.max_entries into the bar at the top.
Press the pencil icon on the far right to modify the number of webpages Firefox can remember.
FYI: learn how to test any Windows antivirus against real malware.
8. Delete Corrupt Website Settings File
Your profile folder holds data in various files as stored by Firefox. If the “content-prefs-sqlite” file that holds individual website settings is corrupted, you may need to delete it to decrease CPU usage.
Click the hamburger menu, and go to Help -> More troubleshooting information to find the corresponding file.
Under Application Basics, click Open Folder next to Profile Folder.
Find and delete the “content-prefs.sqlite” file. Firefox will recreate your profile folder once you launch it again.
9. Use Additional Firefox Troubleshooting Tools
Firefox offers its own Task Manager. Try launching it to see whether tabs or extensions are using too many resources.
Click on the hamburger menu in the top right, and select More tools -> Task Manager.
Once you spot which tabs are using more resources, close these resource-intensive tabs so that you can reduce overall usage.
Refer to the section above to see how to disable extensions.
Once your Firefox browser goes back to working smoothly, you can go about tweaking it. For instance, adjust the scrolling speed in Firefox. Alternatively, you can also block certain websites in Mozilla’s browser.
Image credit: DepositPhotos. All screenshots by Alexandra Arici.
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Alexandra Arici –
Staff Writer
Alexandra is passionate about mobile tech and can be often found fiddling with a smartphone from some obscure company. She kick-started her career in tech journalism in 2013, after working a few years as a middle-school teacher. Constantly driven by curiosity, Alexandra likes to know how things work and to share that knowledge with everyone.
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