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Apache mod_rewrite Errors — URL Rewriting, .htaccess, and Redirect Loop Issues

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Overview

Fix Apache mod_rewrite errors including .htaccess not working, redirect loops, RewriteRule syntax errors, and clean URL routing failures.

Key Details

  • mod_rewrite transforms URLs using regular expressions and rewrite rules
  • .htaccess files allow per-directory configuration but must be enabled with AllowOverride All
  • Redirect loops occur when a RewriteRule matches its own output, creating infinite redirects
  • RewriteCond (conditions) and RewriteRule (actions) work together for URL transformation
  • The [L] flag stops processing further rules; [R=301] sends a permanent redirect

Common Causes

  • AllowOverride set to None in Apache config — .htaccess rules are ignored
  • mod_rewrite module not enabled: 'a2enmod rewrite' not run
  • RewriteRule matching its own rewritten URL causing a redirect loop
  • Incorrect regex in RewriteRule not matching the intended URL pattern

Steps

  1. 1Enable mod_rewrite: 'sudo a2enmod rewrite && sudo systemctl restart apache2'
  2. 2Enable .htaccess: set 'AllowOverride All' in the <Directory> block of your VirtualHost config
  3. 3Test rewrite rules: enable RewriteLog (Apache 2.2) or 'LogLevel alert rewrite:trace3' (Apache 2.4) for debugging
  4. 4Fix redirect loops: add 'RewriteCond %{ENV:REDIRECT_STATUS} 200 [OR] RewriteCond %{REQUEST_URI} ^/target [R=0]' to stop re-processing
  5. 5Verify syntax: 'apachectl configtest' or 'apache2ctl -t' to check for configuration errors

Tags

apachemod-rewritehtaccessredirecturl-rewriting

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Frequently Asked Questions

Most likely AllowOverride is set to None in the Apache VirtualHost config. Change it to AllowOverride All for the document root directory, then restart Apache.