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Disabling Unused WordPress Features

Disabling unused WordPress features can reduce background requests, shrink front-end payload, and lower the attack surface. The key is to disable only what you understand and can test - some "performance" toggles can break checkout, dashboards, or editor behavior.

caution

Test changes on staging first. After each change, purge caches and verify key flows (login, forms, search, cart/checkout, wp-admin).

Quick Wins (Usually Safe)​

These features are commonly disabled on performance-focused sites.

Disable Emojis and Embeds​

If you use Perfmatters, enable its toggles (recommended for simplicity). Otherwise you can use a small MU plugin.

mu-disable-emojis-embeds.php
<?php
/**
 * Plugin Name: MU - Disable Emojis and Embeds
 */

// Emojis
remove_action('wp_head', 'print_emoji_detection_script', 7);
remove_action('admin_print_scripts', 'print_emoji_detection_script');
remove_action('wp_print_styles', 'print_emoji_styles');
remove_action('admin_print_styles', 'print_emoji_styles');
remove_filter('the_content_feed', 'wp_staticize_emoji');
remove_filter('comment_text_rss', 'wp_staticize_emoji');
remove_filter('wp_mail', 'wp_staticize_emoji_for_email');

// Embeds
remove_action('wp_head', 'wp_oembed_add_discovery_links');
remove_action('wp_head', 'wp_oembed_add_host_js');
add_filter('embed_oembed_discover', '__return_false');

Place it in wp-content/mu-plugins/.

Disable Pingbacks / Trackbacks​

disable-pingbacks.sh
wp option update default_ping_status closed

Disable Comments (If You Don't Use Them)​

disable-comments-defaults.sh
wp option update default_comment_status closed
wp option update comment_moderation 0

Tune Instead of Disabling (Commonly Safer)​

Post Revisions​

Instead of disabling revisions entirely, cap them.

cap-post-revisions.sh
wp config set WP_POST_REVISIONS 10 --raw

Autosave​

Instead of trying to remove autosave via theme code, increase the interval.

tune-autosave-interval.sh
wp config set AUTOSAVE_INTERVAL 300 --raw

High-Risk Toggles​

REST API​

Many modern plugins (and WooCommerce) rely on REST endpoints. Disabling it is rarely worth the risk.

If you must restrict it, do it intentionally and test thoroughly.

Example: block REST API for non-logged-in users (use with caution)
restrict-rest-api.php
add_filter('rest_authentication_errors', function($access) {
  if (is_user_logged_in()) {
    return $access;
  }

  return new WP_Error('rest_disabled', 'REST API disabled.', ['status' => 403]);
});

WP-Cron​

Disabling WP-Cron can reduce random background work on page loads, but you must replace it with a real cron.

disable-wp-cron.sh
wp config set DISABLE_WP_CRON true --raw

Example server cron (WP-CLI-based):

crontab-example.txt
*/5 * * * * cd /var/www/html && wp cron event run --due-now --quiet

Validate Your Changes​

  • Confirm constants were written:
confirm-wp-config-constants.sh
grep -E "WP_POST_REVISIONS|AUTOSAVE_INTERVAL|DISABLE_WP_CRON" wp-config.php
  • Use DevTools Network to confirm removed scripts are no longer requested.
  • Re-run PageSpeed Insights for the same URL and compare metrics.

What's Next​