Why Does Mozilla Firefox Make My Processor Usage Go to 100 Percent?

Mozilla Firefox is one of the world's most popular browsers.

Mozilla Firefox is a popular Web browser available on multiple platforms. If you are experiencing problems with Firefox causing 100 percent usage of the Central Processing Unit (CPU), you can try a number of troubleshooting steps. First identify whether the high usage is related to specific Web pages or the Firefox application as a whole, then follow procedures to remedy the situation. Further instructions are available from the Support section of the official Firefox website.

High Usage on Specific Pages

If you are experiencing high CPU usage when using Firefox to browse certain Web pages, a plug-in could be the cause. Make sure you are running the latest versions of the Flash, Adobe Reader and JavaScript plug-ins. Select "Add-ons" from the Firefox menu to view the current plug-ins and check for updates. In addition, a variety of extensions are available from addons.mozilla.org to disable related content on specific sites if the issue persists. Finally, you might want to consider reporting the website via the Feedback button in the top right-hand corner.

High Usage on Every Website

If you are experiencing high CPU usage when using Firefox on every Web page, there are a variety of possible causes. High usage can be caused by hardware acceleration implemented by your graphics card -- consult the documentation supplied with the card for details of how to turn it off. Alternatively, it can be caused by running Firefox in Windows Compatibility Mode -- to disable this, right-click on the firefox.exe file (typically in C:\ Program Files\ Mozilla Firefox), choose "Properties," and deselect the "Run this program in compatibility mode" option under "Compatibility". The Windows Prefetch service can also cause problems -- open up the C:\ Windows\ Prefetch folder on your hard drive and delete all files beginning with "FIREFOX" to see if this resolves the issue.

Troubleshooting Extensions

Firefox extensions can also cause high CPU usage, and you can run Firefox with extensions disabled to see if the issue is resolved. Select "Help" from the Firefox menu, and choose "Restart with Add-ons Disabled" from the sub-menu. You can also try disabling the extensions one by one from the Add-ons Manager (choose "Add-ons" from the Firefox menu to find it) and switching back to the default Firefox theme (visit the "Appearance" tab in the Add-ons Manager) to see if either of these steps solve the problem.

Updating Firefox

It's important to regularly update to the latest version of the Firefox browser, as this version will include all the latest bug fixes and optimizations implemented by the development team. From the main Firefox menu select "Options" and then "Options" again and open the "Advanced" tab. Under "Update" you can configure the software to automatically check for, download and install program updates. The latest version of Firefox can also be downloaded and installed from firefox.com.

References

• Firefox Help: Firefox Consumes a Lot of CPU Resources

Resources

• Firefox: Support Home