Fix: 'Uncaught ReferenceError: $ is not defined' in JavaScript: A Complete Troubleshooting Guide

February 25, 2026

If you are developing a website or customizing a Blogger template and encounter the error 'Uncaught ReferenceError: $ is not defined' in your browser console, you are not alone. This error specifically means that your JavaScript code is trying to use jQuery (which uses the $ shortcut), but the browser cannot find the library. Here is how to fix it step-by-step.

Step 1: Check if jQuery is Included

The most common cause is that the jQuery library hasn't been added to your HTML file at all. JavaScript cannot understand the $ symbol unless the library is loaded first.

  • The Fix: Add the following Google CDN link inside your <head> tag or right before the closing </body> tag:
  • Code: <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>

Step 2: Correct the Script Execution Order

JavaScript files are executed in the order they appear in your HTML document. If your custom script (the one using $) is placed above the jQuery library link, the browser will try to run your code before it knows what jQuery is.

  • The Fix: Ensure that the jQuery library script tag is always placed before your custom <script> tags or external JS files.

Step 3: Resolve Blocked or Broken Links

Sometimes the library is linked correctly, but the browser fails to download it due to a 404 error (broken path) or a Mixed Content error (loading HTTP on an HTTPS site).

  • How to Check: Right-click your page, select Inspect, and go to the Network tab. Refresh the page and look for 'jquery.min.js'. If it is highlighted in red, the link is broken.
  • The Fix: Use a reliable CDN URL (like Google or Cloudflare) and always use https:// to avoid security blocks.

Step 4: Use jQuery.noConflict() Mode

In some environments, like WordPress or complex Blogger templates, the $ sign is reserved for other libraries, causing a conflict. In this case, jQuery might be loaded, but the $ shortcut is disabled.

  • The Fix: Replace $ with the full word jQuery in your script.
  • Example: Instead of $('.button').click();, use jQuery('.button').click();.
  • Alternatively, wrap your code in an IIFE (Immediately Invoked Function Expression) to safely use the dollar sign: jQuery(document).ready(function($) { /* Your code here */ });

Step 5: Move to Vanilla JavaScript (Modern Approach)

If you only need jQuery for simple tasks like selecting elements or adding classes, you can fix the error by removing the dependency on jQuery altogether and using Vanilla JavaScript.

  • Change: $('.element') to document.querySelector('.element')
  • Change: $('.element').addClass('active') to document.querySelector('.element').classList.add('active')
  • This ensures your site stays fast and error-free without needing external libraries.

💡 Pro Tip: Keep your software updated to avoid these issues in the future.

Category: #Website