Firefox Running Slow or Freezing on Mac? Fixes Here

I like using Firefox, one of the most popular web browsers, developed by Mozilla, a non-profit organization.

The Mozilla team has been upgrading the browser by adding many great features, making the product more powerful and easy-to-use.

To date, the latest version of Firefox on Mac is 65.0

However, performance issues about Firefox browser are constantly reported by users.

How many crash reports have you sent to FireFox? I sent quite a few!

I mean, if you have used FireFox on your MacBook Pro for a while, most likely you have encountered issues like page delays, cursor becoming a running pinwheel, unexpected crashes, etc.

As a Firefox user for years, I have had to force quit the browser many times because it’s simply stopped responding.

So, why is Firefox running slow or continuously freezing?

Possible Causes

Depending on the macOS version your MacBook Pro is running, and the Firefox version you use, reasons may vary. But here are some general causes:

  • You are browsing sites that use heavy plugins such as flash, Java scripts, even Adobe Reader. Those plugins are very likely to cause Firefox to freeze.
  • You have opened many tabs and windows while browsing, especially those heavy pages (full of video ads).
  • Too many resource-intensive applications are running, leaving Firefox little space to process your requests.
  • You are using a very old version of Firefox (to be updated).
  • Your Firefox has lots of caches, browsing histories, downloads.
  • Your Macbook is slow in general, making you feel Firefox is the culprit.

How to Fix a Slow or Freezing Firefox on Mac

Step 1: If Firefox becomes totally unresponsive, force quit.

If it turns out that the Mac machine is frozen, you’ll probably have to do a hard reboot by pressing the power button – holding it for three seconds, then press it again to restart your Mac.

Step 2: Open Firefox browser and check the version.

Click the Firefox icon on top left corner, you’ll see “About Firefox”. Click on it and a window will pop up showing you the current version you are using. If it’s not up to date, update it right away.

Step 3: Lighten your browser.

You can do so by:

  • Clearing browsing history (Firefox Menu > History > Clean recent history)

  • Removing useless extensions (Firefox Menu > Preferences > Extensions & Themes > Extensions)

  • Disabling unnecessary plugins (Firefox Menu > Preferences > Extensions & Themes > Plugins)

Step 4: Clean your Mac hard drive.

You can do this manually, or save time by using a dedicated cleaning app likeΒ CleanMyMac X. It will help tune up your overall Mac performance, as well as making Firefox run more smoothly.

Step 5: Better web browsing habits.

Always try to open only one window, and close tabs/pages you don’t need to read, especially when you finish reading content in big magazine sites like Forbes, Huffington Post, MacWorld, etc. which I view as heavy sites because they usually load tons of video ads automatically.

Avoid multitasking at all cost. When you are using Firefox, close as many other apps as possible to squeeze more system resources (CPU, RAM) for Firefox.

Step 6: Switch to an alternative web browser.

Sometimes Firefox just doesn’t work well with certain versions of macOS, for example the previous El Capitan. Many Mac users have observed the performance issue. See more from this thread: Firefox not happy with El Capitan (Apple Discussions)

If Firefox is still running slow or freezing randomly, use an alternative like Google Chrome or Apple Safari though they sometimes act up too.

Anyway, we hope these steps have helped you speed up Firefox a little bit. If you have any further questions, let us know by leaving a comment below.

17 thoughts on “Firefox Running Slow or Freezing on Mac? Fixes Here”

  1. After upgrading my MacBook Pro to macOS Sierra 10.12.2, even after re-installing Firefox 50.1.0, Firefox will at first be quick but then slow down to nothing. I cannot even quit Firefox at that point but have to force-quit it. Very annoying. I have tried everything.
    Klaus

    • Same problem here. At first Firefox is running fast then it starts getter slower and slower. It seems to be crashing the Mac but Mac OS should be stronger than that.

      I am very tired at the poor quality of Sierra and the Mac experience. I am thinking about getting rid of my Mac and go for Windows.

  2. I think the culprit is El Captain, because I am facing this issue since I upgraded to El Captain before that it was running like a charm, I always have dozens of tabs open due to my work requirement but I never experience that on any Mac or PC in past.

    I am going to run Macbooster and delete some extensions (that I can run on chrome).

    thanks admin for telling all possible ways πŸ™‚

  3. Thanks for the tips which I will try. So far have tried resetting firefox, clearing cache, switching off adblock & even switching router channels but nothing has helped. The help pages are confusing & despite numerous attempts haven’t been able to contact anyone in firefox community for help. It’s extremely frustrating & unacceptable. If firefox can’t sort these problems out, it needs to close.

    One big question – why does this keep happening every few months? Getting to the point where I want to switch servers. Can anyone recommend a reliable server?

  4. Tried some of your tips above but it’s still running slow & pages are taking ages to load. Now in the position where I’ve lost stuff that I would have preferred to keep with the added frustration that it’s made no difference! Even typing this message is taking much longer than it should because type takes a long time to appear.

    Thanks admin – feel you are trying to help but I can’t keep wasting time trying to solve this so will have to move to another browser.

    jools

    • Yep, sometimes switching to another browser is the best solution. To be frank, nowadays I use Chrome most of the time πŸ™‚ Thanks for your comment and feedback anyway.

  5. Yeah, Nothing but pinwheels when I click ANYTHING on Firefox on my brand new MacBook Pro w/Touch Bar on Sierra. Will try some of these and see if anything helps. Thanks for this!

  6. I’m finally going to give up on FireFox (after many years)…I just got the spinning wheel there.
    I get the spinning wheel every 20 seconds, and FaceBook is painful sometimes.
    Going to Chrome, I think.

  7. nothing I’ve tried has fixed issues with FFx. I’m on Mavs on a ’13 MBA. Perhaps Mavs is the issue.
    But the latest versions of both Chrome and Safari don’t have any issues other than that they are slower than FFx.
    FFx screams compared to either, but after 15 mins or so the fans crank to 5500 and the CPU is chocked.

  8. My Mac Firefox has been freezing regularly and I’ve tried every suggestion I could find on the Web. Today I saw a suggestion that I hadn’t tried before. Uncheck “use hardware acceleration” in the Preferences/General pane. I now actually think that has solved it. I’ve seen false dawns before, but this looks very promising.

  9. Support I have been a user of Firefox for many years on my MacBook Pro and on ipad.
    I have a high speed internet provider and get good results using a test called Brebandskollen, but get a much slower result with firefox.Can you advise me what I can do to improve the speed.

    Thank you from a
    82 year old user.

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