On first load, why does Firefox take 4 seconds to render the page.
In Firefox 42.0 loading several .js files seems to take a long time.
It only happens when you first open Firefox and visit the website, if you press refresh or hold Ctrl and Press F5 it works fine.
It seems to take 1/2 a second to load each .js file.
We have tested the same website in Firefox 40 and it appears to be ok and also in other browsers and they work fine as well.
The only difference on this website compared to others is that they have a https version, although we are loading the website via http
We set up a file on the same domain that doesn't have the website on, but literally a few elements and a few very basic JS files which can be found here: http://www.joshuajamesjewellery.co.uk/index-james.php
The more JS files you add the longer it takes to load.
It affects Windows 7 and Windows 10 and not just our office.
All Replies (8)
Yes, the more js files the more omtc has to load into the page before it displays.
The JS files load for me in about 100 ms in Firefox 42.
It is possible that firewall or Anti-Virus software is causing problems. Try to disable security software temporarily to see if that makes a difference.
I have Windows 10, with only the Windows Defender that comes with it. It is also affecting 3 different machines in and out of the office, that all have different setups, all have different anti virus, its only happened since Firefox 42 so its got to be Firefox that is causing the issue.
Just in case i disabled Windows Defender and tried again with no change.
guigs said
Yes, the more js files the more omtc has to load into the page before it displays.
The page i linked you to has 4 or 5 JS files, that have one line of JS in that sets the document title, surely that should not slow the site down.
I have sites with Mootools and several JS files that load fine, it only appears to be this site and this is the only site that has a HTTPS version.
cor-el said
The JS files load for me in about 100 ms in Firefox 42. It is possible that firewall or Anti-Virus software is causing problems. Try to disable security software temporarily to see if that makes a difference.
Sorry, the JS files do load in about 68ms for me but if you wait until the site has finished loading the load event takes 10 seconds, so its about 1/2 second per JS file. Again this only happens if you close Firefox and then open Firefox and go to the page. Pressing refresh it loads instantly.
I have also enabled Safe mode in Firefox and the problem solves itself. I have then followed the procedure of disabling add-ons, hardware acceleration etc... but the issue continues to happen.
You can check for problems with preferences.
Delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in current Firefox releases.
cor-el said
You can check for problems with preferences. Delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in current Firefox releases.
Thanks, just tried the method of deleting the prefs.js file, it then created a fresh version when i opened Firefox, still same problem. Strangely when it created the new prefs.js file a lot of the settings were still set to 'user set' so it looks like that doesn't reset them all to default. The issue is its happening on PC's out of my office and i cant expect customers to an online store to perform this procedure.