WP-Cron
Quick Definition
WP-Cron is WordPress's built-in task scheduler that runs scheduled jobs — like publishing scheduled posts, checking for updates, and sending emails — by checking for due tasks on every page load instead of using a real server cron.
What Is WP-Cron?
WordPress's pseudo-cron that checks for due tasks on every page load. Powers scheduled posts, update checks, backup schedules, database cleanup, and email sending.
How It Works
- Plugin/core registers task with
wp_schedule_event() - Saved with timestamp + interval
- Every page load checks
wp-cron.php - Overdue tasks execute during that request
- Task rescheduled for next interval
The Problem
Depends on page loads. Low traffic = late tasks. High traffic = unnecessary DB checks on every request.
Fix: Real Cron
- Add to wp-config.php:
define('DISABLE_WP_CRON', true); - Set server cron every 15 min:
*/15 * * * * wget -q -O - https://yourdomain.com/wp-cron.php?doing_wp_cron >/dev/null 2>&1
Reliable schedule + no per-page overhead.
Why It Matters
Fine for most sites. Switch to real cron for high-traffic or e-commerce where scheduled tasks are critical. Fixes missed posts, late backups, and page speed overhead.
Sources: Developer.WordPress.org, Kinsta