Use a Real Cron Job for WordPress (Disable WP-Cron)
WordPress runs scheduled tasks via wp-cron.php, which only fires when someone visits the site — unreliable on low-traffic sites and wasteful on busy ones. Disable it and call wp-cron.php from a real system cron on a fixed schedule.
Step 1: disable the built-in wp-cron
In wp-config.php add:
define('DISABLE_WP_CRON', true);
Step 2: add the system cron line
crontab -e, then (every 15 minutes):
*/15 * * * * /usr/bin/curl -fsS https://example.com/wp-cron.php?doing_wp_cron >/dev/null 2>&1
Or run it via PHP CLI without HTTP: */15 * * * * cd /var/www/html && /usr/bin/php wp-cron.php >/dev/null 2>&1.
Which interval?
Every 15 minutes suits most sites. If you rely on WooCommerce scheduled actions or frequent publishing, every 5 minutes is safer. Don't go below 1 minute.
FAQ
How do I replace WP-Cron with a real cron job?
Add define('DISABLE_WP_CRON', true); to wp-config.php, then run */15 * * * * curl -fsS https://site/wp-cron.php?doing_wp_cron from system cron.
Why is WordPress cron unreliable?
wp-cron only runs when a page is visited, so scheduled posts and tasks are late on low-traffic sites. A real system cron fires on a fixed schedule regardless of visits.
How often should the WordPress cron run?
Every 15 minutes is fine for most sites. Use every 5 minutes if you depend on WooCommerce actions or frequent scheduled publishing.