Get the speed benefits of loading jQuery (and jQuery Migrate) from a CDN while providing a fallback to the local version in the event the CDN is down. It also uses the same version as WordPress does – automagically, so you’re never out of sync.
Loading jQuery from cdnjs
By default, jQuery is loaded from Google with jQuery Migrate being loaded from cdnjs. If you’d like to also load jQuery from cdnjs, add the following to wp-config.php
define('WPJP_USE_CDNJS', true);