by Smashing Media
Aug 18 2009

10+ Mod_Rewrite Rules You Should Know

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Mod_rewrite is an Apache-based rewrite engine for dynamically rewriting URLs. It’s built into Apache servers natively, though not enabled by default.

It’s capable of functions beyond simple rewrites, though, some of which are included below.

Mod_Rewrite Rules You Should Know

Turn Mod_Rewrite On

Mod_rewrite is used through your .htaccess file. Place the following code at the beginning of your .htaccess file to turn mod_rewrite on:

RewriteEngine on

(Don’t forget that .htaccess commands are case-sensitive.) This code needs to be entered at the beginning of any .htaccess file using mod_rewrite.

The Basic Mod_Rewrite Layout

The basic format for a mod_rewrite command is:

RewriteRule Pattern Substitution [Flag(s)]

URLs are Always Relative

The URL you redirect to is always relative to the directory in which your .htaccess file is placed. So if it’s in the root directory, URLs are all in relation to the root directory; if it’s in a sudirectory, URLs are in relation to that particular subdirectory.

A Basic Redirect

If you just want to create a simple 301 redirect from one URL to another, then use the following code:

RewriteRule ^fileone.html$ filetwo.html

This is a very basic rule that means any requests for fileone.html will be sent to filetwo.html.

Require no “www”

This bit of code will make it so visitors to your site don’t need to type in the “www” bit of your website address.

RewriteCond %{HTTP_HOST} !^domain\.com$ [NC]
RewriteRule ^(.*)$ http://domain.com/$1 [R=301,L]

Block a Specific IP Address

If you want to block someone coming from a specific IP address from accessing your website, you can use the following code:

RewriteCond %{REMOTE_ADDR} ^(A\.B\.C\.D)$
RewriteRule ^/* http://www.domain.com/sorry.html [L]

Replace the A\.B\.C\.D with the IP address you want to block (don’t forget to leave the “\” before each dot, which escapes the character).

Block Specific User Agents

If you want to block a group of IP addresses using the same User Agent (bot), the following code with do it:

RewriteCond %{HTTP_USER_AGENT} UserAgent
RewriteRule .* - [F,L]

Just replace the “UserAgent” bit with whatever user agent you want to block. You can also block more than one at a time by replacing the top line in that code with something like this:

RewriteCond %{HTTP_USER_AGENT} UserAgentA [OR]
RewriteCond %{HTTP_USER_AGENT} UserAgentB

You can put as many user agents in as you want, just make sure you end each line with [OR] (with the exception of the last line, of course).

Strip Query Strings

Let’s say all the pages on your site other than your home page are formatted as follows, with query strings instead of page names:

http://www.domain.com/home.html?example=12345abcd

Those aren’t very pretty, and on top of that, search engines will show a bunch of duplicated “home” pages. If you want to get rid of the query string in your page URLs, use the following code:

RewriteCond %{QUERY_STRING} example=
RewriteRule (.*) http://www.domain.com/$1? [R=301]

This not only gets rid of the query string, but also the preceding question mark.

Set up a Default Image

Using a default, backup image in case of broken images can make your site look more professional. Use the following code to redirect to a default image for any image whose file cannot be found.

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^images/.*\.jpg$ /images/default.jpg [L]

Of course, you can change the “.jpg” bit to whatever file type you’re using. Make sure you have an image called “default.jpg” or change that to whatever your default image filename is.

Prevent Hotlinking

The last thing most website owners want is other sites stealing their content or worse—hotlinking to their images and stealing their bandwidth. Here’s a simple bit of code that prevents it:

RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain.com/ .*$ [NC]
RewriteRule \.(gif|jpg|swf|flv|png)$ /feed/ [R=302,L]

Make sure you change the “domain.com” bit to your own domain name.

Redirect to a Maintenance Page

If you need to take your entire site offline for a bit and redirect to a maintenance page (or some other page), use the following code:

RedirectMatch 302 ^/ /maintenancepage.html

Change the “maintenancepage.html” bit to wherever your maintenance page file is located.

Redirect Multiple Domains to a Single Domain

If you have multiple domains pointing to your site, it’s possible you could take a hit in the search engines for having duplicate content. Use the following code to redirect visitors from two domains to just one:

RewriteCond %{HTTP_HOST} ^www.domain.net$ [NC,OR]
RewriteCond %{HTTP_HOST} ^domain.net$ [NC,OR]
RewriteCond %{HTTP_HOST} ^www.domain.net$ [NC]
RewriteRule ^(.*)$ http://domain.net/$1 [R=301,L]

Remember the Filesystem Always Takes Precedence

The filesystem on your server will always take precedence over the rewritten URL. For example, if you have a directory named “services” and within that directory is a file called “design.html”, you can’t have the URL redirect to “http://domain.com/services”. What happens is that Apache goes into the “services” directory and doesn’t see the rewrite instructions.

To fix this, simply rename your directory (adding an underscore to the beginning or end is a simple way to do that).

Remember:

  • Because mod_rewrite works within the .htaccess file, commands are case sensitive.
  • Always back up your .htaccess file before making any changes to it. This way, if there’s a problem, you can easily restore your site.

More Resources:

Author: Cameron Chapman

Cameron Chapman is a writer, blogger, copyeditor, and social media addict. She’s been designing for more than six years and writing her whole life. If you’d like to connect with her, you can follow her on Twitter or at her Personal Website.

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Comments and Discussions

  • Web Design Bureau of Mauritius, 18 August 2009

    Great roundup Cameron. I had to use those when I swapped domain names and succeeded in getting back a PR 3 in 3 weeks while I left a PR 5 domain name astray.

    • Rob, 08 July 2010

      NICE Tute… I haven’t ever seen such a thorough, and simple tute on this subject..

      Much Love,

      Graphicalinsight

  • Julien, 18 August 2009

    Thanks. Those are always helpful.

  • yasser, 18 August 2009

    Thanks alot for this article ..

    we hope to see more from noupe & cameron ..

  • Jim Gaudet, 18 August 2009

    Damn, how to not sound spammy.

    Great list!

    That didn’t work. Anyway, this was one worth saving and sharing..

    Thanks,

    • Cory, 18 August 2009

      Well, i guess my comment sounds spammy too :)

  • Cory, 18 August 2009

    Just on time, thanks a lot for this great post :)

  • Paul Decowski, 18 August 2009

    RedirectMatch is a mod_alias directive, not mod_rewrite (in Redirect to a Maintenance Page).

  • Daniel, 18 August 2009

    I find it extremely ironic that you mention a rewrite for setting up default images (Quote: Using a default, backup image in case of broken images can make your site look more professional.) and yet down at the bottom of the page, under every comment, is a broken image…

  • Joltivan, 18 August 2009

    thanks, I looking for this :)

  • Doug Bell, 19 August 2009

    Great list, but you should be careful: Some of these things are better off not using mod_rewrite.

    Redirect, Alias, and are also useful tools that are usually enabled by default.

  • Ahmed, 19 August 2009

    the problem im facing in wordpress how ican add www in the url

    • prafuitu, 19 August 2009

      This is what you are looking for:

      RewriteCond %{HTTP_HOST} ^domain-name\.tld$ [NC]
      RewriteRule ^(.*)$ http://www.domain-name.tld/$1 [R=301,L]

  • tintedPixel, 19 August 2009

    How about a mod_rewrite Fix for Controlling updated files and Caches:

    RewriteCond %{THE_REQUEST} ^(GET|HEAD)\ /z/([a-z]+)/(.+)-([0-9]+)\.(js|css).*\ HTTP/ [NC]
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule .+ /z/%2/%3.%5 [NC,L]

    or

    Cache-Friendly File Names that allow you to update javascript and css files in my visitors cache’s simply by naming them differently in the html, on the server they stay the same name.

    RewriteRule ^directory/(j|c)/([a-z]+)-([0-9]+)\.(js|css)$ /directory/$1/$2.$4 [L]

  • richard, 19 August 2009

    thank you so much for this post! I have been meaning to consolidate my .com and .me domains, and strip the www. prefix — you’ve helped me do exactly that, and also disable hotlinking and add in maintenance page references for future use. Thanks again!!

  • John Moray, 19 August 2009

    Remember to never put rewrite rules in .htaccess because they will be interpreted and compiled at each request, which is something neither you and your hosting service want.

  • prafuitu, 19 August 2009

    * URLs are Always Relative – FALSE. URLs are relative to the current directory only if no RewriteBase directive is used, in which case the URLs become relative to the specified path. (http://httpd.apache.org/docs/2.0/mod/mod_rewrite.html#rewritebase) Also, you can use absolute URLs by specifyng the protocol to be used.

    * …so visitors to your site don’t need to type in the “www” bit… – WRONG. That has nothing to do with making the “www” optional. It’s related to SEO, creating a single entry-point to your website by redirecting all your visitors (including search engines) to your “domain-name.tld”. This way, the search engines won’t index the same page twice, making it lose its strength.
    This rule should be accompanied by a rule to remove file names such as “index.php”, “index.php5″, “index.asp”, “index.htm”, “index.html”, “default.html”, etc, which all point to the same page, the homepage. If a user can see the homepage on multiple different URLs, so can a search engine, which will index it as X different pages (X being the number of available URLs for the homepage)
    You should be using something like this:
    RewriteRule (index|home|default)\.([a-zA-Z0-9]{3,4})$ / [R=301,L]

    Also, 302 is “Found” while 301 is “Permanently Moved”. They are both redirects but the second should be used for permanent rules. The second tells the crawler to “forget” this URLs as the resource associated with it has been moved to the new location and that is the URL that it should be using from now on. The first one just says: “Ok, for now, what you are looking for has been moved someplace else, but you should check this URL again in the future as the resource might become available again”

    Also, I don’t agree with the statement that “a default image would make your site look more professional in case of a broken image URL”… You could say, at best, that it would make your site look less dilettantish, as a professional wouldn’t have broken links on any of his pages. :P

    * Remember the Filesystem Always Takes Precedence – are you absolutely sure about that? ‘Cause I’m pretty sure that if I have this rule:

    RewriteRule ^dir-name(.*)$ file-name.php [NC,L]

    and I try to access http://my-domain.tld/dir-name/other-file.html, even though there is an other-file.html in a dir-name, I will get the contents of file-name.php
    I’m sure about that because I use this in all of my projects and I always have to specify which folders I want to exclude from my rules. E.g: I redirect absolutely everything to the index.php file (which acts as a bootstrap file) and I use something like:

    RewriteRule ^assets(.*)$ – [NC,L]

    to allow users to access the contents of the “assets” folder, where I usually keep the image/css/javascript files…

    These being said, I’ll give you the “thumbs up” for the initiative and, sadly, a “thumbs down” for the quality of the content… :(

    • prafuitu, 19 August 2009

      I forgot this…

      Let aside the fact that RedirectMatch is a mod_alias directive, not a mod_rewrite, there is no way your example would ever work, because any “maintenance” file name you would use, it would be matched by the given regex, resulting in a neverending redirect…

      What you could use instead is:

      RewriteCond %{REQUEST_URI} !maintenance.html$ [NC]
      RewriteRule .* /maintenance.html [R=302,NC,L]

      However, this would also block users to access the images or css files, so you will have to add more RewriteConds to that set, making it look something like:

      RewriteCond %{REQUEST_URI} !^/css [NC]
      RewriteCond %{REQUEST_URI} !^/images [NC]
      RewriteCond %{REQUEST_URI} !^/js [NC]
      RewriteCond %{REQUEST_URI} !^/maintenance.html$ [NC]
      RewriteRule .* /maintenance.html [R=302,NC,L]

      • Bruce L, 01 February 2011

        Thank you so much for this – exactly what I was looking for.

        I’ve been searching for hours looking for how to allow the images to show on my outage page, realizing they were caught in a redirect loop.

    • iFlash, 03 June 2011

      Can I get a contact Mr. Prafuitu?

  • derschreckliche, 19 August 2009

    So this one will Block IE6, right?

    RewriteCond %{HTTP_USER_AGENT} ‘MSIE6′
    RewriteRule .* – [F,L]

    • superdit, 23 August 2009

      oupp yes now i know to block IE6 thanks

  • Nick, 19 August 2009

    Thanks for the article. I’m a mod-rewrite newbie struggling with an issue…

    I have a current directory path:
    http://www.mysite.com/blah/page.php?specialcode=123456

    I want to redirect all attempts to blah/ to http://www.mysite.com/new/index.php?page=new-page&specialcode=123456 and want to retain the special code included in the initial URL.

    I’ve essentially re-written a complete section of the site in a mini-MVC model and need to convert traffic going to the old pages to the new model. I can do this in PHP, but want to completely get rid of blah/ and never look at it again.

    Any help would be appreciated.

    Thanks,
    Nick

  • Nick, 19 August 2009

    Thanks for the article. Im a mod-rewrite newbie struggling with an issue…

    I have a current directory path:
    http://www.mysite.com/blah/page.php?specialcode=123456

    I want to redirect all attempts to blah/ to http://www.mysite.com/new/index.php?page=new-page&specialcode=123456 and want to retain the special code included in the initial URL.

    I’ve essentially re-written a complete section of the site in a mini-MVC model and need to convert traffic going to the old pages to the new model. I can do this in PHP, but want to completely get rid of blah/ and never look at it again.

    Any help would be appreciated.

  • Kaplang, 20 August 2009

    thanks for the post, really useful stuff :)

  • hossein, 21 August 2009

    hi
    it was a good tutorial

    i have an old problem with htaccess and i wonder if you could help me whith it. please please please please help

    i want to do this with my htaccess
    the role :

    1 – users request a url like : test.mysite.com
    2- apache should know show mysite.com/test

    BUT idont want the user to see the second url in his/her addressbar can you help me?

    thanks
    if you had any thing to say please mail me and let me know . thanks again

  • Lit_Tiger, 28 August 2009

    Thanks , Useful post

  • Http Referer, 02 September 2009

    You can easily rewrite requests for resources that are not processed by ASP.NET by default, such as those for image files, for example. Http Referer

  • Asad, 16 December 2009

    Hi,

    suppose, there is a url
    http://www.domain.com/asad
    I want to redirect it to
    http://www.domain.com/folder1/folder2/folder3/asad

    Can any one help me, how is this possible,

    Thanks

    Asad

  • Dominica, 29 January 2010

    Hi people

    How do i hide every fileextensions like .php or .asp or .html etc
    i want like this

    from mydomain.com/send.php?t=abc&k=123 to
    mydomain.com/send?t=abc&k=123

    thanks

  • Anup, 13 March 2010

    Thanks for these cool tips.

  • Jos, 14 April 2010

    Excelente articulo, gracias. Muy buenos algunos para aplicar.

  • cash boxes combination lock, 19 April 2010

    Couldn´t be written any kind of much better. Reading that post reminds me of my old room mate! He continually kept talking about this. I can forward that article to him. Really certain he will use a great read. Thanks for sharing!

  • Mohit, 27 April 2010

    Thanks a lot! very useful infomation.

  • Rich Bowen, 24 May 2010

    Please don’t link to the 1.3 version of the mod_rewrite docs. Please instead link to http://httpd.apache.org/docs/trunk/rewrite

    We’ve been working very hard to make them more accurate and more useful, and it’s very frustrating to find articles like this linking to the 1.3 docs which are significantly out of date.

  • Saddle Dressage, 27 July 2010

    Thank you. Got this link through BHW. Helped a lot to get a basic understanding of mod_rewrite. Now I know what I am doing. :)

  • Alberto Douglas, 11 August 2010

    Thanks a lot! very useful infomation,was looking for a tutorial as simple as this.

  • Inception 2010, 11 September 2010

    Hats off for the ingenius post. kudos!

  • fds, 28 September 2010

    know something

  • fds, 28 September 2010

    hehe

  • Brett Widmann, 24 October 2010

    Great set of tips and nice code! Thanks for sharing

  • Ajay, 26 November 2010

    Thanks , thank u very much. its very easy to understand

  • Irvin Pumper, 27 November 2010

    Evening i just came across your site from Google but got a strange popup about cat hospitals which is obviously not related to your site. Is this your ads or do i have a spyware issue? Thanks.

  • shohan, 07 December 2010

    just,i was searching for this type of article..
    mod rewrite is cool !! thanks writer !

  • Sourav, 10 December 2010

    If i have a page like this “www.yoursite.com/game.php?id=123″ and I want to show the url as “www.yoursite.com/game/123″ what should I write? Can anyone email me?

    There are several pages in this domain which I want same kind of redirection. Whats the method?

  • share your talent, 01 February 2011

    I’ve truly appreciated reading your articles. You obviously know what you are talking about! Your internet site is so effortless to navigate as well, I’ve bookmarked it in my favourites :-D

  • Brian Norman, 21 February 2011

    How do i redirect a request for http://my_server/cgi-bin/xxx
    back to the requesters ip eg http://hackers_ip/cgi-bin/xxx
    ?

  • Mark, 05 April 2011

    Thank you for this article, it really helped to stop an iPhone developer from harvesting the latest lottery numbers from our website at http://www.alottery.com each time a user accessed their app – up until now it has been eating almost 2Gb a month in bandwidth.
    Keep up the good work, love the site!

  • Kaushik Biswas, 20 April 2011

    I need a little help. Every day I find some visitors using Googlebot as their browser’s User Agent while visiting my site. I want to stop the fake Googlebots. How can I allow the real ones and keep out the fake ones? Is there any way to do this via htaccess?

  • Jatin, 30 April 2011

    Few of the rules mentioned here are really cool. Thanks.

  • Anoir Hama, 19 May 2011

    Helpful tutorial, thx for the explanation, by the way I’m stuck on redirecting Html/php sample pages with no DB to .Aspx/.pl/.do or any other extension :S

    Example:
    website.com/index.php or index.html
    to: website.com/index.do or any other perfect extension
    Please help me to rewrite rules on the file .htaccess

    (!) You can also keep in touch with me or email me at: x.genius.y@gmail.com

  • sajin, 10 August 2011

    Hai,

    I wan a small help if you can

    My site url is http://localhost.com/view/vendor?name=sajin

    In this view is a Page
    and vendor is a function inside the same page

    i wan to rewrite the url to http://localhost.com/sajin

    sajin will change dynamicall as its users name

  • muhammed sekertekin, 20 October 2011

    wow very nice article it helps me a lot iam now removing all the query string in my website i was told it will help me rank in search engines muhammed sekertekin

  • Robert, 19 November 2011

    I am trying to redirect
    kategorier?uid=[number]
    to
    index.php?option=com_comprofiler&task=userProfile&user=[number]
    but it does not work, what am i doing wrong?
    RewriteRule kategorier\?uid=([0-9]+) index.php?option=com_comprofiler&task=userProfile&user=$1 [R=301,L]

    Regards Robert

  • tyler, 11 December 2011

    Unfortunately this did not help me with my issues. Thanks though

  • ahmadMarafa, 17 January 2012

    thanks for your post , that’s really help
    but how to avoid css,js and images dirs reWriten ?

    thanks for help

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