RewriteEngine On RewriteCond %{HTTP_ACCEPT} image/webp RewriteCond %{REQUEST_FILENAME} -f RewriteRule . - [E=REWRITEBASE:/] RewriteRule ^(.*)\.(jpe?g|png)$ %{ENV:REWRITEBASE}modules/pshowlazyimg/webp-on-demand.php?source=%{SCRIPT_FILENAME} [NC,L] AddType image/webp .webp