How to Add Google AdSense to WordPress Easily

Put AdSense Code Manually in Child Theme

If you are searching for how to put Google AdSense code in WordPress, use your child theme’s functions.php file instead of editing header.php directly. When you update your parent theme, changes inside header.php will be overwritten, whereas child theme files persist indefinitely.

1. Log in to your WordPress dashboard. Navigate to Appearance > Theme File Editor.
2. Select your active Child Theme from the top dropdown menu.
3. Open the functions.php file.
4. Paste the PHP hook snippet shown below at the end of the file.
5. Replace YOUR ADSENSE SCRIPT HERE with your auto-ads tag.

add_action('wp_head', 'mza_add_adsense_code');
function mza_add_adsense_code() {
?>
<!-- Replace with your actual Google AdSense Script -->
<script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-XXXXXXXXXXXXXXXX" crossorigin="anonymous"></script>
<?php
}

Configuring ads.txt and Auto Ads

Optimize Ad Layouts for Cumulative Layout Shift (CLS)

Cumulative Layout Shift (CLS) happens when dynamic ad containers inject content without holding initial space. The surrounding content shifts downward unexpectedly, degrading user experience and lowering your Core Web Vitals score.

Fix CLS penalties by defining structural placeholders with explicit dimensions or modern CSS aspect-ratio values:

.ad-container {
  width: 100%;
  aspect-ratio: 728 / 90;
  overflow: hidden;
  background: transparent;
}

For standard leaderboards, use 728x90. For mobile banner slots, reserve a minimum height using min-height: 250px to lock layout bounds prior to script execution.