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

Mozilla Firefox 55 is running slow on Mac OS X 10.9

  • 2 cavab
  • 1 has this problem
  • 6 views
  • Last reply by cor-el

more options

Installed Mozilla 55 on Mac OS X 10.9 and the pages are loading slow . It takes about 2 or 3 minutes to load a page . need a solution for this issue .

Installed Mozilla 55 on Mac OS X 10.9 and the pages are loading slow . It takes about 2 or 3 minutes to load a page . need a solution for this issue .

All Replies (2)

more options

Any reason you are sticking with Mac 10.9? It's old, insecure and unsupported by Apple.

more options

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

  • switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
  • do NOT click the "Refresh Firefox" button on the Safe Mode start window

You can try to modify multi-process settings to see if this has effect.

  • set dom.ipc.processCount to 1 if it is currently set to a higher value (4)
  • disable multi-process windows in Firefox

You can disable multi-process windows in Firefox by setting these prefs to false on the about:config page.

  • browser.tabs.remote.autostart = false
  • browser.tabs.remote.autostart.2 = false

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.


Try to disable IPv6 (check for other possible causes as well).

Modified by cor-el