-RewriteCond %{REQUEST_FILENAME} !-f
-RewriteCond %{DOCUMENT_ROOT}/$1.plp -f
-RewriteRule ^/*([^/]+)(.*) $1.plp$2
+RewriteCond %{REQUEST_FILENAME} !-f
+RewriteCond %{DOCUMENT_ROOT}/$1.plp -f
+RewriteRule ^/*([^/]+)(.*) $1.plp$2
+
+# replace jpeg images by webp alternatives if supported
+RewriteCond %{HTTP_ACCEPT} \bimage/webp
+RewriteCond %{DOCUMENT_ROOT}/$1.webp -f
+RewriteRule (.*)\.jpg$ $1.webp