When not to use mod_rewrite

... SSL configuration goes here

This document supplements the modrewritereference documentation. It describes perhaps one of the most important concepts about modrewrite - namely, when to avoid using it.

modrewrite should be considered a last resort, when other alternatives are found wanting. Using it when there are simpler alternatives leads to configurations which are confusing, fragile, and hard to maintain. Understanding what other alternatives are available is a very important step towards modrewrite mastery.

Note that many of these examples won't work unchanged in your particular server configuration, so it's important that you understand them, rather than merely cutting and pasting the examples into your configuration.

The most common situation in which

is the right tool is when the very best solution requires access to the server configuration files, and you don't have that access. Some configuration directives are only available in the server configuration file. So if you are in a hosting situation where you only have .htaccess files to work with, you may need to resort to mod_rewrite

allows you to include a regular expression in your redirection criteria, providing many of the benefits of using RewriteRule

is to redirect an entire class of URLs. For example, all URLs in the /one

directory must be redirected to http://one.example.com/

requests must be redirected to https

These situations are better handled by the Redirect

preserves path information. That is to say, a redirect for a URL /one

will also redirect all URLs under that, such as /one/two.html

and /one/three/four.html

ServerName www.example.com Redirect / https://www.example.com/ ServerName www.example.com # ... SSL configuration goes here

to perform this task may be appropriate if there are other RewriteRule

directives in the same scope. This is because, when there are Redirect

directives will run first, regardless of the order of appearance in the configuration file.

would be appropriate if you don't have access to the main server configuration file, and are obliged to perform this task in a .htaccess

Alias /cats /var/www/virtualhosts/felines/htdocs

Symbolic links would be another way to accomplish the same thing, if you have Options FollowSymLinks

to create these hosts automatically.modvhostalias

are also useful for creating a large number of virtual hosts dynamically.mod_macro

for vitualhost creation may be appropriate if you are using a hosting service that does not provide you access to the server configuration files, and you are therefore restricted to configuration using mod_rewrite.htaccess

See the virtual hosts with mod_rewrite document for more details on how you might accomplish this if it still seems like the right approach.

RewriteRule ^/?images(.*) http://imageserver.local/images$1 [P]

However, in many cases, when there is no actual pattern matching needed, as in the example shown above, the

directive is a better choice. The example here could be rendered as:ProxyPass

directive to catch redirects issued from the back-end server:ProxyPassReverse

will usually take effect before a ProxyPass

, and so may preempt what you're trying to accomplish.

is used to enforce a canonical hostname, such as www.example.com

This technique can be used to take actions based on any request header, response header, or environment variable, replacing

See especially the expression evaluation documentation for a overview of what types of expressions you can use in sections, and in certain other directives.

Modules | Directives | FAQ | Glossary | Sitemap

Apache HTTP Server Version 2.4