Firefox uses too much memory or CPU resources - How to fix
At times, Firefox may require significant system resources in order to download, process, and display web content. If you are experiencing periods of sustained high resource usage while using Firefox, this article presents some options for you to review.
- The CPU (Central Processing Unit) is the "brain" of the computer.
- The RAM (Random Access Memory) or Memory helps your computer perform multiple tasks at the same time.
- When your system resources are being heavily used, the overall performance and stability of the computer can be impacted.
- Depending on your operating system, you can review and monitor resource usage through specific tools. See the Use additional troubleshooting tools section below for more information.
Table of Contents
- 1 Update to the latest version
- 2 Restart Firefox
- 3 Disable resource consuming extensions and themes
- 4 Hide intrusive content
- 5 Check Firefox hardware acceleration
- 6 Check Flash hardware acceleration
- 7 Use fewer tabs
- 8 Close other applications
- 9 Delete corrupt content-prefs.sqlite file
- 10 Refresh Firefox
- 11 Use additional troubleshooting tools
- 12 Add RAM to your computer
- 13 Upgrade your computer
Update to the latest version
The latest Firefox version may include performance improvements. Update Firefox to the latest release.
Firefox may use more system resources if it's left open for long periods of time. A workaround for this is to periodically restart Firefox. You can configure Firefox to save your tabs and windows so that when you start it again, you can start where you left off. See Restore previous session - Configure when Firefox shows your most recent tabs and windows for details.
Disable resource consuming extensions and themes
Extensions and themes can cause Firefox to use more system resources than it normally would.
To determine if an extension or theme is causing Firefox to use too many resources, start Firefox in its Safe Mode and observe its memory and CPU usage. In Safe Mode, extensions and themes are disabled, so if you notice a significant improvement, you can try disabling or uninstalling extensions.
- For more information on starting Firefox in Safe Mode and on how to find which extension or theme is causing your problem, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.
Hide intrusive content
Many web pages have content you don't need, but which still use system resources to display its content. Firefox's built-in content blocking can help save resources by preventing third-party tracking content from loading. See the Content blocking article for details.
Some extensions allow you to block unnecessary content; for example:
- Adblock Plus and uBlock Origin allow you to hide ads on websites.
- NoScript allows you to selectively enable and disable scripts running on websites.
Check Firefox hardware acceleration
Firefox hardware acceleration eases memory and CPU usage in many cases.
Check Flash hardware acceleration
If Adobe's Flash Player plugin is installed, rendering Flash content in full screen can be accelerated by hardware. This can ease resource usage in case of a dedicated graphics card.
- Navigate to a page that shows a Flash video.
- Right-clickHold down the Ctrl key while you click on the video player and click in the context menu. The Adobe Flash Player Settings screen will open.
- Click on the icon at the bottom-left of the Adobe Flash Player Settings window to open the Display panel.
- Check Enable hardware acceleration is selected.
- Click to close the Adobe Flash Player Settings Window.
Use fewer tabs
Each tab requires Firefox to store a web page in memory. If you frequently have more than 100 tabs open, consider using a more lightweight mechanism to keep track of pages to read and things to do, such as:
- Bookmarks. Hint: "Bookmark All Tabs" will bookmark a set of tabs.
- Save web pages for later with Pocket for Firefox.
- To-do list applications.
Close other applications
Having many applications running simultaneously may cause your computer to run slowly and other applications to do so as well. By closing down some of the unnecessary applications, system usage will be reduced.
Delete corrupt content-prefs.sqlite file
Firefox stores your data in various files in your profile folder. The file used for saving individual website settings might be corrupt. If you delete that file, your zoom level settings will be reset, but it should decrease CPU usage.
Click the menu button , click and select .From the The Troubleshooting Information tab will open. menu, choose .
Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
- Under the Application Basics section, click on A window will open that contains your profile folder.Your profile folder will open. .
Click the menu button and then click ExitQuit .
Click the Firefox menu , then click .Click the Firefox menu at the top of the screen, then click .Click the Firefox menu , then click .
- In your profile folder, delete the file content-prefs.sqlite. It will be recreated next time you open Firefox.
The Refresh Firefox feature can fix many issues by restoring your Firefox profile to its default state while saving your essential information. See Refresh Firefox - reset add-ons and settings for details.
Use additional troubleshooting tools
There are a variety of troubleshooting tools that can be used both in Firefox and on your operating system to troubleshoot elevated system resource usage.
- The Firefox Task Manager (not to be confused with Windows Task Manager) is a great tool to see what tabs and extensions are using the most system resources.
- The about:memory page allows you to troubleshoot specific issues relating to memory (for instance, caused by a website, an extension, a theme, etc.) and sometimes its about:memory. button may help you instantly reduce memory usage. For guidance on use of about:memory visit
- Even if you're not a programmer, you can try your hand at some other tools and tips Firefox developers use to debug leaks.
Operating system tools
- View how system resources are being used by checking Activity Monitor. See How to use Activity Monitor on your Mac at Apple's site for more information.
- Although it's not included on every distribution of Linux, most versions of Linux have a graphical resource monitor. It's often called System Monitor, but there are other alternatives also available.
- Running the
topcommand in the terminal will display a list of all the running processes and their system resource consumption.
Add RAM to your computer
If you exhausted all tips in the previous sections and your memory usage is still close to the maximum, maybe it's time for you to add more memory to your computer. Adding RAM will provide a huge performance boost.
Upgrade your computer
If you exhausted all tips in the previous sections and you are still experiencing high system resource usage, it may be time to upgrade your computer. As technology progresses, software is becoming more advanced and requires more powerful computers to run effectively.