.htaccess Tester

How Apache reads an .htaccess file

An .htaccess file applies its rules to requests for the directory it sits in. Rewrite rules in this per-directory context see the URL path relative to that directory, without the leading slash. That is why RewriteRule ^about$ … matches /about in a root .htaccess, while RewriteRule ^/about$ … never matches. This tester assumes the file is in the document root.

Apache works through the rules from top to bottom. Each RewriteRule has a pattern tested against the path and, optionally, one or more RewriteCond lines directly above it. All the conditions must pass, unless they are joined with [OR]. When a rule matches, its substitution replaces the URL.

Internal rewrites and redirects

A substitution without the R flag is an internal rewrite: the visitor’s address bar does not change, but the server serves a different file. In per-directory context Apache then runs the rules again on the new URL, and keeps going until nothing changes. A rule like RewriteRule ^(.*)$ /index.php [L] without a condition that stops it on the second pass is a classic cause of the “too many internal redirects” error. The END flag stops that extra pass entirely.

With the R flag, Apache sends the browser to the new URL instead. Use R=301 for permanent moves. A plain R sends a 302, which tells search engines the old URL is still the one to keep. Always add L as well, otherwise Apache carries on processing later rules before redirecting.

RewriteEngine On

# Send http and www to https://example.com, in one hop
RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^www\.example\.com$ [NC]
RewriteRule ^(.*)$ https://example.com/$1 [R=301,L,NE]

Query strings

The pattern of a RewriteRule never sees the query string. Test it with RewriteCond %{QUERY_STRING}. If the substitution contains a ?, the new query replaces the old one unless you add QSA to append the original. QSD discards it. On a redirect without either, Apache keeps the original query.

Back-references

$1 to $9 refer to groups captured by the rule pattern. %1 to %9 refer to groups captured by the last condition that matched. The www redirect below uses the host name captured by its condition.

RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L]

Redirect chains and loops

Every extra redirect hop costs a round trip, and search engines follow only a limited number of them. If one rule moves HTTP to HTTPS and another then moves www to non-www, many URLs take two hops. Combine them so every old URL reaches its final address directly. The tester follows each redirect through your rules and reports chains and loops.

Rules for a migration

Map every old URL to the most relevant new URL with a 301, rather than sending everything to the home page, which search engines tend to treat as a soft 404. Keep the redirects in place for at least a year. The generator tab writes the common patterns. Test the result here, then on a staging server, before going live.