Gzipped content expected

Question

I enabled gzip compression on my website, and tested with the following tools:

• http://www.whatsmyip.org/http_compression/
• http://www.gidnetwork.com/tools/gzip-test.php
• http://web-sniffer.net/

Though, Firefox and all its extensions (Firebug, Yslow and Google Page Speed) say they receive noncompressed content.

text/html is compressed by php's ob_gzhandler, which cares about headers as well.

I don't use proxy.

What am I doing wrong?

Answer 1

That's not really the answer you might expect, but did you try not compressing out data with PHP, but with Apache ?

This can be done use mod_deflate.

Couple of things :

• it would mean less calculations for PHP
• it would also mean (and that's the nicest part ;-) ) that your CSS/JS files could be compresses to ; considering the size of those, nowadays, it might not be a bad thing to compress them...

As a sidenote : to help us figure out what's going wrong with the compression by PHP, could you give more informations ? Like the URL of your site (if it's public), and some code ?

---

EDIT now that we have the URL : http://ego.pestaa.hu/

When I go to that page, the response's headers are as follow :

HTTP/1.x 200 OK
Date: Sat, 01 Aug 2009 21:53:37 GMT
Server: Apache
X-Powered-By: PHP/5.2.6
**Content-Encoding: gzip**
Vary: Accept-Encoding
Keep-Alive: timeout=2, max=100
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html

(using firefox 3.5 with LiveHTTPHeaders extension)

The three testing sites you indicated also say that your page is gzipped.
Did you find what the problem was ?

Are you sure this is not something coming from your browser, that would not send the following header in the request :

Accept-Encoding: gzip,deflate

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EDIT after other answer

Quote from the comments :

the source of problem probably isn't my website but my isp/browser/router. One of them may decompress every component before it reaches internal processes.

Oh, if the problem is not your website, I think I totally mis-understood the question -- sorry about that :-( I thought you didn't know how to server gzipped content from your website.
And I think I'm not the only one, btw

If the problem has nothing to do with your website's configuration, then, two possibilities :

• maybe a mis-configuration of firefox ? If you go to about:config, what does the network.http.accept-encoding say ? For me, it's gzip,deflate
• if the problem is coming from your ISP or something like that, there's nothing anyone can do...

Answer 2

Try the Live Http Headers firefox plugin in addition to the others. It opens a window showing the exact request/response headers as they go back and forward, so you know without doubt what the accept-encoding and response-encoding is.

Answer 3

Have you tried just enabling gzip in Apache/your web server instead/as well?

Answer 4

• Are you sure you're testing the same URLs with the Firefox extensions?
  • Using the ob_gzhandler in PHP will compress the output of your php pages, but YSlow and others warn you also about uncompressed css/javascript files.
• Check that the browser is sending the correct headers. A browser usually sends the "Accept-encoding: gzip" header to tell the script/webserver it accepts compressed content. The testing scripts will surely send that but your browser might not.