Bootstrap Dropdown menu is not working

html

responsive-design

best-practices

web-development

byAnton Shumikhin·Oct 7, 2024

To ensure your Bootstrap Dropdown operates properly, you need correct integrations with Bootstrap's JS and CSS. Bootstrap dropdowns specifically require jQuery or Bootstrap's own JS. Here's a clean, functioning setup:

<!-- He who doesn't wear Bootstrap's styles, has no styles at all.  -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">

<!-- jQuery first, then Bootstrap JS - the 'chicken and egg' of coding. -->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.bundle.min.js"></script>

<!-- Behold, the structure of the dropdown men-u-topia. -->
<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Menu
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <a class="dropdown-item" href="#">Link 1</a>
    <a class="dropdown-item" href="#">Link 2</a>
  </div>
</div>

Just a reminder, cross-verify that your button has data-toggle="dropdown" and also browse the JS console for error messages that might hinder the scripts.

Troubleshooting steps

Checking Bootstrap and jQuery file links

Study the source links of your CSS and JS files. Are they retrieving the correct resources? Make sure correct version files from a reliable CDN are being used.

Cross-check your dropdown's HTML structure with the structure outlined in Bootstrap's official documentation. A single misplaced attribute can stiffen your dropdown.

Verifying script load order

Remember the ancient truth, jQuery should always come before Bootstrap's JS. The load sequence of scripts decides the fate of your dropdown.

Identifying conflicts with other libraries

Got other JS libraries in the play too? They might conflict with jQuery. Use jQuery.noConflict() to make sure $ is all jQuery's.

Implementing cross-browser testing

Shake hands with different browsers, say Hi to Chrome, Safari, Firefox, et al. Confirm that dropdown behaves consistently across the board.

Tackling incompatibility issues

Are you keeping up with Bootstrap? Using an outdated version can cause feature malfunction. Always check Bootstrap, jQuery, and Popper.js version compatibility.

Seeking external help

Tried everything? Banged your head to the wall (figuratively)? Now, it is the moment to consult the community or seek professional help.

Best practices

Proper placement of tags

The placement of jQuery script tag should always precede Bootstrap's JS. Order does matter, it decides if your dropdown will pop (pun intended) or not.