Control WordPress Heartbeat API

The Heartbeat API fires AJAX requests every 15-60 seconds to keep sessions alive, autosave posts, and detect simultaneous editing. On sites with many admin users, this can overwhelm the server with constant admin-ajax.php requests.

control-heartbeat.php

<?php
/**
 * Control WordPress Heartbeat API
 *
 * The Heartbeat API fires an admin-ajax request every 15-60 seconds on
 * every admin page. This keeps the server busy with requests that are only
 * useful on the post editor (for autosave and lock detection). This snippet
 * disables Heartbeat everywhere except the post editor and slows it down
 * there to reduce server load.
 *
 * Usage: Add to functions.php.
 *
 * @category performance
 * @language php

 *
 * @author Adame Dahmani https://adame.io
 * @support Support my family project: https://adame.io/fundraiser
 */
add_action( 'init', function () {
    if ( ! is_admin() ) {
        wp_deregister_script( 'heartbeat' );
        return;
    }

    global $pagenow;

    if ( $pagenow !== 'post.php' && $pagenow !== 'post-new.php' ) {
        wp_deregister_script( 'heartbeat' );
    }
}, 1 );

add_filter( 'heartbeat_settings', function ( $settings ) {
    $settings['interval'] = 60;
    return $settings;
} );

This disables Heartbeat on the frontend entirely, keeps it only on the post editor (where autosave matters), and slows it to 60-second intervals. The result: fewer AJAX requests without losing autosave protection.