Manipulating HTTP Headers with htaccess

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<FilesMatch "\.(html|htm|js|css)$">
FileETag None
<IfModule mod_headers.c>
Header unset ETag
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
</IfModule>
</FilesMatch>

<FilesMatch "\.(html|htm)$">
<IfModule mod_headers.c>
Header set imagetoolbar "no"
</IfModule>
</FilesMatch>

<IfModule mod_headers.c>
Header set P3P "policyref=\"/w3c/p3p.xml\", CP=\"NOI DSP COR NID CUR ADM DEV OUR BUS\""
# OR THIS, SIMPLER
Header set P3P "policyref=\"/w3c/p3p.xml\""
</IfModule>

AddDefaultCharset UTF-8
AddLanguage en-US .html .htm .css .js

AddType 'text/html; charset=UTF-8' .html

<Files ~ "\.(htm|html|css|js)$">
AddDefaultCharset UTF-8
DefaultLanguage en-US
</Files>

<FilesMatch "\.(htm|html|css|js)$">
AddDefaultCharset UTF-8
DefaultLanguage en-US
</FilesMatch>

Reader Comments

1. Tylan ~

   Does this work for EXE files as well?

2. Tylan ~

   Will the Prevent Caching 100% work for executables? I have an EXE on our site that I use for remote support. I frequently update it, but I want to make sure that that my end users always download the current version, and not one in their cache.

   Tylan

3. WiserX ~

   I surf the net for an easy to understand guide on htaccess.

   Finally i have a deeper idea on htaccess with your guide.

   Intelligent work. Thanks.

4. AskApache ~

   @ Jackson

   Thanks for spotting that, I updated the .htaccess example code above to use the IfModule directive to prevent the 500 Errors, nice one bro.

5. Mike ~

   Thank you for this amazing wealth of knowledge! It’s more definitive (and easier to understand) than the main apache and php.net forums.

   QUESTION:
   You suggest “prevent file caching” to speed up a site. Doesn’t turning OFF caching slow down the site? Seems it’s faster to pull a file from cache than request it …unless I’m missing or confusing this with something else?

   Thanks again! -Mike

6. Jackson ~

   Just a note for “100% Prevent Files from being cached“:
   You need to enable mod_headers otherwise it drops

   500 Internal Server Error

7. Brian’s Web Design ~

   I’m just wondering about this P3P. I read about it, and was wondering if any browser implements this?

8. johnny ~

   I have multiple folders inside an assets folder that contain mp3 & swf files that I do not want to cache. this is my htaccess code not sure if im using it correctly

   RewriteEngine on
   rewritecond %{http_host} ^ninjatactics.net [nc]
   rewriterule ^(.*)$ http://www.ninjatactics.net/$1 [r=301,nc]
    
   FileETag None
   Header unset ETag
   Header set Cache-Control "max-age=0, no-cache, no-store, private"
   Header set Pragma "no-cache"
   Header set Expires "0"

9. AskApache ~

   @ johnny

   use the http header viewer tool to see if its working, if not then paste your .htaccess

10. johnny ~

    i am using the “100% Prevent Files from being cached” htaccess code but not sure i am using it correctly. I created the file in placed it in the root directory. do i need to specify where my files are locate in the htaccess file?

11. AskApache ~

    @ Daniel

    Works for me.. the http-equiv meta tag literally means http header equivelant. http header is better of course.

12. Daniel ~

    imagetoolbar = no
    doesn’t works, you have to specify the “http-equiv” explicitly. Why that?

13. karel ~

    Does ‘100% Prevent Files from being cached’ also works for websites displaying ads in an php environment instead of html?

It's very simple - you read the protocol and write the code. -Bill Joy

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