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Can anyone help me figure this.

If I use this compression test it tells me my site uses gzip. But when I run the yslow Firefox plugin it tells me my site does not use gzip.

Has anyone came across this before? Is there a more conclusive test I could do?


The site in question is http://www.thefootytipster.com, if you copy and paste that into the first link it will say compression is enabled. But if you try it against ySlow it will not.

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No -- have not seen that before. It will be much better if you provide some real URL (at least to some test page that reports difference like that). – LazyOne Jul 30 '11 at 14:25
What I'm thinking: the compression may be sensitive to User Agent string (you have not provided exact settings .. so I assume it is a possibility). – LazyOne Jul 30 '11 at 14:42
up vote 4 down vote accepted

Are you definitely testing the same URLs? If you are inputting your domain into one testing tool, then that checks if the home page on your site (ie the HTML) is sent gzipped.

But if you open the page in Firefox and run Yslow it will check all linked files as well. Your HTML pages may be gzipped (probably as a result of a CMS) but CSS and JavaScript may not be compressed.

Make sure to check in each tool exactly which URLs it says are not gzipped.

share|improve this answer
+1. Home page (HTML) is gzipped while css files are not. @Toby YSlow as well as Google PageSpeed shows you the exact URLs that are not compressed - 100% sure on this one. – LazyOne Jul 30 '11 at 15:05

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