how to remove WordPress cron jobs

Understanding WordPress Cron Jobs

WordPress cron jobs play a crucial role in how WordPress handles scheduling time-based tasks. These tasks can range from publishing scheduled posts to performing routine plugin checks. However, excessive cron jobs can slow down your website. Learning how to efficiently manage and remove unnecessary cron jobs is essential for optimizing your website performance.

Identifying Existing Cron Jobs

To manage WordPress cron jobs effectively, you first need to identify them. This can be done using a plugin or via code.

Using a Plugin:
Plugins like WP Crontrol make it easy to view and manage cron jobs. Once installed, navigate to Tools > Cron Events to see a list of all scheduled cron events. Here, you can see essential details such as the individual cron event names, recurrence, and the next run.

Using Code:
For those who prefer not to use a plugin, you can add the following code to your theme’s functions.php file to display cron jobs:

add_action( 'admin_notices', 'list_cron_jobs' );
function list_cron_jobs() {
    $cron_jobs = get_option( 'cron' );
    echo '
' . print_r( $cron_jobs, true ) . '
';

}
This code snippet will output the array of scheduled cron events at the top of your admin dashboard.
Removing Unwanted Cron Jobs
Via Plugin:

Using WP Crontrol, you can click on the “Delete” option next to the cron job you want to remove. This is straightforward and does not require any coding knowledge.
Via Code:

If you identify a cron event that is no longer necessary, you can unschedule it using the wp_clear_scheduled_hook function. Place the following in your functions.php:
add_action( 'wp_loaded', 'remove_custom_cron_job' );
function remove_custom_cron_job() {
    $hook_name = 'name_of_the_cron_job_hook';
    wp_clear_scheduled_hook( $hook_name );
}
Replace 'name_of_the_cron_job_hook' with the actual hook name of the cron job you wish to remove.
Managing Plugin-Related Cron Jobs
Plugins often schedule their cron jobs. If you deactivate or delete a plugin, ideally, its cron jobs should automatically be removed. However, some plugins might not clean up their cron jobs upon deactivation. 
To manually remove these:

Identify the plugin-specific hook name from the WP Crontrol list or the array displayed using the code.
Use the wp_clear_scheduled_hook() function as described above to remove these hooks.

Optimizing Cron Jobs for Site Performance
While removing unnecessary cron jobs, it’s also wise to fine-tune necessary ones to optimize performance:

Adjust the schedule: Less critical events can be rescheduled to run less frequently.
Cron Spawning: WordPress cron works on a visitor-based system, which means it checks for cron jobs to execute on every page load. To reduce this load, consider setting up a real cron job through your server’s control panel.

Setting Up a Server Cron Job:

Disable WP-Cron by adding define('DISABLE_WP_CRON', true); to your wp-config.php.
Set up a system crontab by accessing your hosting control panel or via command line. For example:
* * * * * wget -q -O - http://yourdomain.com/wp-cron.php?doing_wp_cron >/dev/null 2>&1
This command would trigger WordPress cron jobs manually every minute.


Final Thoughts on Management
Regular review and management of WordPress cron jobs ensure that your website remains speedy and performs optimally. Tools like WP Crontrol can be very effective for users not comfortable with code. However, understanding and utilizing code for cron management provides flexibility and reduces dependency on plugins, which itself can contribute to a faster admin dashboard and website.
Managing cron jobs wisely can decrease server resources consumption and, consequently, enhance your site’s overall performance and user experience.