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Firefox on Windows loads the same site significantly more slowly than Firefox on Mac, across multiple computers

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I'm experiencing a very strange problem where the same website consistently loads slowly on Firefox for Windows but it loads at a normal speed on Firefox for Mac. This problem occurs on multiple computers. The website is https://www.cwds.pa.gov and I'm using Firefox 26.

If I open up Network in the Developer tools and check the Timings for the page, I see that Firefox on Windows generally spends >30 seconds on the PublicHomePage.aspx file. Looking for more detail under Timings, I see that most of the time is spent receiving the file. I might be mistaken, but if the problem lies in the server sending the file slowly shouldn't the aspx file also take a similar amount of time in Firefox for Mac?

Also, I don't experience this problem when using IE9 on the same PCs that experience this problem. So far it's happened on multiple Windows computers, some of them VMs and some of them actual hardware.

I'm not the author of this web site, but I'm trying to support users who are attempting to access the site. To me it seems like something weird is going on in the Windows build of Firefox, given that the Mac build works ok and other browsers on the same computer also load the page fine. It is a government web site, though, so it could just be some unusually horrible markup causing the problem. :) Thanks!

I'm experiencing a very strange problem where the same website consistently loads slowly on Firefox for Windows but it loads at a normal speed on Firefox for Mac. This problem occurs on multiple computers. The website is https://www.cwds.pa.gov and I'm using Firefox 26. If I open up Network in the Developer tools and check the Timings for the page, I see that Firefox on Windows generally spends >30 seconds on the PublicHomePage.aspx file. Looking for more detail under Timings, I see that most of the time is spent receiving the file. I might be mistaken, but if the problem lies in the server sending the file slowly shouldn't the aspx file also take a similar amount of time in Firefox for Mac? Also, I don't experience this problem when using IE9 on the same PCs that experience this problem. So far it's happened on multiple Windows computers, some of them VMs and some of them actual hardware. I'm not the author of this web site, but I'm trying to support users who are attempting to access the site. To me it seems like something weird is going on in the Windows build of Firefox, given that the Mac build works ok and other browsers on the same computer also load the page fine. It is a government web site, though, so it could just be some unusually horrible markup causing the problem. :) Thanks!

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Hello,

Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache. Note: This will temporarily log you out of all sites you're logged in to. To clear cache and cookies do the following:

  1. Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
  2. Under "Time range to clear", select "Everything".
  3. Now, click the arrow next to Details to toggle the Details list active.
  4. From the details list, check Cache and Cookies and uncheck everything else.
  5. Now click the Clear now button.

Further information can be found in the Clear your cache, history and other personal information in Firefox article.

Did this fix your problems? Please report back to us!

Thank you.

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Thanks for your response. I tried clearing cookies and the cache on two systems, but it did not resolve the problem. Internet Explorer loads the site in about a second on both clients, but according to Firefox's network monitor the site took >80 seconds on one client and >122 seconds on the other. Also, I should add that I do not have a proxy configured in Firefox (nor does my network environment require one).

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Hello,

Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.

(If you're not using it, switch to the Default theme.)

  • On Windows you can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
  • On Mac you can open Firefox 4.0+ in Safe Mode by holding the option key while starting Firefox.
  • On Linux you can open Firefox 4.0+ in Safe Mode by quitting Firefox and then going to your Terminal and running: firefox -safe-mode (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)
  • Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

FirefoxSafeMode

Once you get the pop-up, just select "'Start in Safe Mode" Safe Mode Fx 15 - Win

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.

Thank you.

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That page doesn't load for me as well with Firefox 26.0 on Linux.
Firefox makes request for files, but this server takes a lot of time to respond and it took about 163 seconds to load the page.
I used "Forget About This Site" and loaded thepage anothr time and now it took 350 seconds to fully load with only 397 KB downloaded.
Content does appear quicker if I reload the page another time (F5) with a lot less requests.

It is possible that IE loaded a lot of files from the disk cache if you have visited the site before (try a hard reload with Shift+F5 in IE).

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The problem is still present in safe mode in Firefox. The site loads fine in Internet Explorer both with a hard reload and after clearing the cache completely. I tried this out on two computers that had never visited this site before.