GZip Discrimination Test

Because of general incompetence and lack of testing, several sites fail to ensure they compress (either gzip or deflate) the content they send for some browsers but not others; sometimes sites deliberately target browsers for such treatment. This online test checks using a variety of different user-agent strings whether compression browser discrimination occurs. It will follow HTTP redirects, but not meta redirects so that is something to be aware of. Opera users can use this button to easily test a site (drag it up to a toolbar of your choice): GZip-Test

Report for: http://www.cb-talk.de/

  1. Opera 9.0 : Opera/9.00 (Windows NT 5.1; U; en)

    Compressed! Transfer size: unknown

    HTTP/1.1 200 OK
Date: Thu, 29 Jul 2010 11:22:19 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Encoding: gzip
Vary: Accept-Encoding
Set-Cookie: PHPSESSID=51bfefc403ece26d4b771171d0ad64cc; path=/
Set-Cookie: PHPSESSID=296536079c2bb9030e499ba4b3dc5bd5; path=/
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1

    cURL Time: 0.883619

  2. Opera 9.0 (ID: MSIE 6.0) : Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; en) Opera 9.00

    Compressed! Transfer size: unknown

    HTTP/1.1 200 OK
Date: Thu, 29 Jul 2010 11:22:19 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Encoding: gzip
Vary: Accept-Encoding
Set-Cookie: PHPSESSID=fd2d79bc978828b37211e3def34ceab9; path=/
Set-Cookie: PHPSESSID=173c68afb47a2019fa84bc6173ddbf60; path=/
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1

    cURL Time: 0.453141

  3. MSIE 6.0 : Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)

    Compressed! Transfer size: unknown

    HTTP/1.1 200 OK
Date: Thu, 29 Jul 2010 11:22:20 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Encoding: gzip
Vary: Accept-Encoding
Set-Cookie: PHPSESSID=ab12cbb1b4f54897ca47807123be2885; path=/
Set-Cookie: PHPSESSID=2ae7eeaa4386d2e5d1695100b45691df; path=/
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1

    cURL Time: 1.126995

  4. Firefox 1.0 : Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.8) Gecko/20050511 Firefox/1.0

    Compressed! Transfer size: unknown

    HTTP/1.1 200 OK
Date: Thu, 29 Jul 2010 11:22:21 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Encoding: gzip
Vary: Accept-Encoding
Set-Cookie: PHPSESSID=880d099099435115357ef5ce2b2cfdb2; path=/
Set-Cookie: PHPSESSID=59d2ef4eeb9826d0809c8c414661c0c3; path=/
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1

    cURL Time: 0.393974

  5. Safari v125 : Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en) AppleWebKit/124 (KHTML, like Gecko) Safari/125

    Compressed! Transfer size: unknown

    HTTP/1.1 200 OK
Date: Thu, 29 Jul 2010 11:22:21 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Encoding: gzip
Vary: Accept-Encoding
Set-Cookie: PHPSESSID=e075203632ea8511855dd65234e790f0; path=/
Set-Cookie: PHPSESSID=be88bf10d51cb2c8e68b428e09172274; path=/
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1

    cURL Time: 0.389613



You can test the following (default is ozmfs):
----------------------------------------------------
	o  Opera 9.0
	m  MSIE 6.0
	f  Firefox 1.0
	n  Netscape 8.0 (Gecko)
	z  Opera 9.0 spoofed as MSIE 6.0
	x  Opera 9.0 spoofed as Mozilla
	w  Opera 9.0 spoofed as MSIE 6.0 BUT with Opera written Opura
	s  Safari v125
	y  Safari v125 spoofed as MSIE 6.0
	k  Konqueror 3.1