get_extensions_pattern(); $home_root = wp_parse_url( home_url( '/' ) ); $home_root = $home_root['path']; return trim( ' location ~* ^(' . $home_root . '.+)\.(' . $extensions . ')$ { add_header Vary Accept; if ($http_accept ~* "webp"){ set $imwebp A; } if (-f $request_filename.webp) { set $imwebp "${imwebp}B"; } if ($imwebp = AB) { rewrite ^(.*) $1.webp; } }' ); } }