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My CPU usage rises when I go to certain websites using Firefox.

  • 9 replies
  • 1 has this problem
  • 4 views
  • Last reply by cor-el

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Basically, if I go to a certain website my CPU usage raises drastically. Slowing down my PC. I switched to Firefox because Chrome stopped working on my computer, and I loved it, so I kept using it.

But now, I'll have to use... Internet Explorer... Unless I can fix this problem. But I used these browsers because they're fast and allow me to do what I need.

If you know what's causing this problem, I'd be really appreciative if you could let me know.

Basically, if I go to a certain website my CPU usage raises drastically. Slowing down my PC. I switched to Firefox because Chrome stopped working on my computer, and I loved it, so I kept using it. But now, I'll have to use... Internet Explorer... Unless I can fix this problem. But I used these browsers because they're fast and allow me to do what I need. If you know what's causing this problem, I'd be really appreciative if you could let me know.

All Replies (9)

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What websites are you having problems with? What is on those pages? Ads, Clips?


Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

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It varies on each website. Some websites use 60% of my CPU (YouTube )others only use 20% (This forum).

Safemode did not help unfortunately.

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FredMcD said

What websites are you having problems with?
What is on those pages? Ads, Clips?
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I gave examples. Though it happens on every website. And since it happens on every site that means there will be ads and videos on some of them.

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Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?


Does this add-on make any difference?.

Flash block {web link} Never be annoyed by a Flash animation again! Blocks Flash so it won't get in your way, but if you want to see it, just click on it

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The add-on didn't help. And as I said in my first reply Safe mode doesn't change anything.

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I wouldn't have posted this if any of those worked. It prompts you before you post giving you similar problems.

Anyways, I appreciate your help.

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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