This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox eats up 25% of my CPU and over 50% of my memory; the problem persists for several minutes after I close Firefox, and the fixes I found haven't worked.

  • 13 replies
  • 6 have this problem
  • 1 view
  • Last reply by OCyrus

more options

Whenever I open Firefox it eats about 25% of my CPU and over 50% of my memory, even if I have nothing else running and only have one tab open with no active content. At times it gets up over 1 million KB of memory usage. This persists for several minutes after I close Firefox. In addition, I have searched Firefox support for other solutions and nothing has worked to reduce this.

Whenever I open Firefox it eats about 25% of my CPU and over 50% of my memory, even if I have nothing else running and only have one tab open with no active content. At times it gets up over 1 million KB of memory usage. This persists for several minutes after I close Firefox. In addition, I have searched Firefox support for other solutions and nothing has worked to reduce this.

All Replies (13)

more options

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. Is the problem still there?

more options

FredMcD said

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. Is the problem still there?

Yes.

more options

Interesting.

Start your Computer in safe mode with networking. Then start Firefox. Try Safe websites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

more options

Yes. I had seen this solution in the forums before and tried it, but it still used up the same amount of memory even in Safe Mode. I also removed several add-ons and plug-ins, have the default theme, and tried limiting cookie storage and memory usage in the settings.

more options

Any other ideas?

more options

I've called the big guys to help you. Good luck.

more options

Thank you.

more options

Create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

You can check for issues caused by plugins.

  • set plugins to "Ask to Activate" on the about:addons page ("3-bar" menu button or Tools > Add-ons > Plugins)
  • plugins are not affected by Firefox Safe Mode
more options

I tried making a new profile and left Firefox running with a page open. Sure enough, its memory usage began climbing, though not quite to where it was. I have run some additional virus scans recommended in your post to remove some bad files, and have set Flash Player to Ask to Activate, not sure if that works yet. As I type this Firefox is pushing 400k kb with six tabs open.

more options

What web pages do you have open? Try with just one page. After a time, open a second. Later, a third.

more options

One tab isn't bad, but opening a second tab increases the CPU usage by 15-20%. Leaving this tab open with an email application open as well increased Firefox's memory usage from 285k to 320k kb. Additionally, this problem with it increasing my memory usage to unreasonable levels is new to the past two or three months.

more options

Are there clips or many pictures? Please post some of those links so we can check them out.

more options

Facebook and Youtube are common for me, but this morning when I replied it was this page and Outlook email. I can also leave it open only on pages without pictures such as http://www.metal-archives.com/release/upcoming and achieve the same result of the memory usage increasing dramatically as I leave the page open.