Recently I was asked to look into an issue for a Macintosh user, using Safari. It seems that some of the pages on one of my clients sites was not loading very swiftly. As I started looking into the issue I decided to take a baseline using Internet Explorer 6 on a Windows XP box. Then I moved to Firefox. When I got to Firefox, sure enough several pages were taking more than a minute to load, in some cases more than 3 minutes. These sames pages loaded in under 20 seconds using IE and Opera.
Next I fired up a Macbook and took a look at the same site using Safari. Low and behold I had the same issue as Firefox on my Windows box. So I decided to test the site with Firefox and Opera for Macintosh, and again Firefox was slow and Opera was fast.
To add to the problem, I found that testing the development versions of this site ran without a problem in all of the browsers. So I started thinking of what differences existed between the two environments. The biggest difference being that production has an added network appliance that validates you are allowed to access the page you have requested. But even with that in mind the question remains, why would IE and Opera be able to request and receive a response quicker than Firefox and Safari?
As it turns out, I happened to notice that some of the URLs a user would click on were open-ended directories.
However, if I were to change that link to be:
Notice that I added a / after the directory named "Reports".
After making the change, the page loaded in seconds on all of four browsers. While I have not confirmed it yet, I suspect that part of the problem is related to how each browser sends the HTTP Request, and that part of the problem was with the network appliance.