How to Fix WordPress ‘jQuery is not defined’ Error (6 Ways)

Understanding the “jQuery is not defined” Error in WordPress

The “jQuery is not defined” error in WordPress is a common JavaScript error that indicates the jQuery library, crucial for many WordPress themes and plugins, isn’t loading correctly or at all. This error typically manifests as broken functionality, distorted layouts, and JavaScript-dependent features failing to work. Identifying the root cause is the first step to resolving this issue.

This error occurs because JavaScript code is trying to use jQuery functions before the jQuery library has been fully loaded into the browser. jQuery is a fast, small, and feature-rich JavaScript library that simplifies HTML document traversing and manipulation, event handling, animation, and Ajax. Many WordPress themes and plugins rely heavily on jQuery for their dynamic elements and interactive features.

Several factors can contribute to this error, including:

• jQuery not being enqueued correctly in WordPress.
• Problems with the order in which scripts are loaded.
• Conflicts with other JavaScript libraries.
• Using the `$` shortcut before jQuery is ready.
• A faulty theme or plugin causing the issue.
• Issues with your Content Delivery Network (CDN).

When this error occurs, the browser console (accessible via Inspect Element) will display messages like “Uncaught ReferenceError: jQuery is not defined” or “TypeError: $ is not a function.” Understanding these error messages is key to pinpointing the source of the problem. Ignoring this error can severely impact the user experience and functionality of your WordPress site.

Method 1: Ensure jQuery is Properly Enqueued

One of the most common causes of the “jQuery is not defined” error is incorrect or missing jQuery enqueueing. WordPress has a built-in system for managing JavaScript files, including jQuery. Using this system, known as the WordPress enqueue system, ensures that scripts are loaded in the correct order and avoid conflicts.

The correct way to add jQuery to your theme or plugin is through the `wp_enqueue_scripts` action. Avoid directly linking to jQuery from a CDN or adding `