Solve - $(...).autocomplete is not a function jQuery Error


Borislav Hadzhiev

Last updated: Oct 19, 2021


Check out my new book

Solve - $(...).autocomplete is not a function #

The "$(...).autocomplete is not a function" jQuery error occurs for multiple reasons:

  1. Forgetting to include the jQuery UI library.
  2. Loading the jQuery UI library before the jQuery library.
  3. Loading the jQuery library twice.
  4. Specifying an incorrect path to the jQuery files.

To solve the "$(...).autocomplete is not a function" jQuery error, make sure to load the jQuery library before loading the jQuery UI library. The libraries have to be loaded only once on the page, otherwise the error is thrown.

<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <!-- ✅ Load CSS file for jQuery ui --> <link href="" rel="stylesheet" /> </head> <body> <div class="ui-widget"> <label for="tags">Tags: </label> <input id="tags" /> </div> <!-- ✅ load jQuery ✅ --> <script src="" integrity="sha256-/xUj+3OJU5yExlq6GSYGSHk7tPXikynS7ogEvDej/m4=" crossorigin="anonymous" ></script> <!-- ✅ load jQuery UI ✅ --> <script src="" integrity="sha512-uto9mlQzrs59VwILcLiRYeLKPPbS/bT71da/OEBYEwcdNUk8jYIy+D176RYoop1Da+f9mvkYrmj5MCLZWEtQuA==" crossorigin="anonymous" referrerpolicy="no-referrer" ></script> <script src="index.js"></script> </body> </html>

The order the scripts are loaded in is very important. We loaded the scripts in the following order:

  1. jQuery UI css stylesheet
  2. jQuery library
  3. jQuery UI library
  4. our own index.js file

Here's the code for the index.js file.

$(document).ready(function () { $(function () { var availableTags = [ 'ActionScript', 'AppleScript', 'Asp', 'BASIC', 'C', 'C++', 'Clojure', 'COBOL', 'ColdFusion', 'Erlang', 'Fortran', 'Groovy', 'Haskell', 'Java', 'JavaScript', 'Lisp', 'Perl', 'PHP', 'Python', 'Ruby', 'Scala', 'Scheme', ]; $('#tags').autocomplete({ source: availableTags, }); }); });

If you open the page you will see an input field with working autocomplete.

The error most commonly occurs if you forget to load the jQuery UI library or load the jQuery library twice.

Loading the jQuery library twice re-runs the initialization and causes the error.

If you're loading the libraries from files on your local file system, make sure that you're specifying the correct path.

Specifying an incorrect path when loading a script is the same as not loading the script at all and leads to the error.

You can check if you're loading the libraries correctly by opening the console in your browser.

If you see any 404 errors related to the jQuery and jQuery UI scripts, then the path is specified incorrectly.

I wrote a book in which I share everything I know about how to become a better, more efficient programmer.
book cover
You can use the search field on my Home Page to filter through all of my articles.