Bootstrap 4 drops support for Internet Explorer 8 and 9, but you can add it back by simply adding a conditional statement targeting IE 8 and 9 with a CSS file and a CDN-hosted JavaScript file to polyfill HTML5 element support.
Several quick start options are available:
- Download the latest release
- Clone the repo
git clone https://github.com/coliff/bootstrap-ie8.git - Install with npm
npm install bootstrap-ie8 - Install with yarn
yarn add bootstrap-ie8 - Install with Composer
composer require coliff/bootstrap-ie8:4.3.1
-
Add
<meta http-equiv="x-ua-compatible" content="ie=edge">to the top of the of your page -
Add the following conditional statements to the
<head>of your page but after the Bootstrap 4 CSS:
<!--[if IE 9]>
<link href="https://cdn.jsdelivr.net/gh/coliff/bootstrap-ie8/css/bootstrap-ie9.min.css" rel="stylesheet">
<![endif]-->
<!--[if lte IE 8]>
<link href="https://cdn.jsdelivr.net/gh/coliff/bootstrap-ie8/css/bootstrap-ie8.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/g/[email protected]"></script>
<![endif]-->To fix the dropdown menus and modals you can add the following to the footer:
<!--[if gte IE 9]><!-->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"></script>
<!--<![endif]-->
<!--[if IE 9]>
<script src="https://cdn.jsdelivr.net/gh/coliff/bootstrap-ie8/js/bootstrap-ie9.min.js"></script>
<![endif]-->
<!--[if lte IE 8]>
<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/coliff/bootstrap-ie8/js/bootstrap-ie8.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.js"></script>
<![endif]-->This will load jQuery, PopperJS and Bootstrap as normal on all browsers other than IE8.
IE9 will load the bootstrap-ie9.js script.
IE8 will load the latest compatible version of jQuery, the unminified Bootstrap JS (the minified version causes an error) and the bootstrap-ie8.js fix.
Q. What does this fix/polyfill?
A. Internet Explorer 9 doesn't support flexbox so there is a float-based layout fallback and a couple of other minor fixes. Internet Explorer 8 doesn't support rem units so all units are specified in pixels. Media Queries are also not supported so IE8 has a fixed-width layout (min-width 998px).
Q. Is the CSS hosted on a CDN?
A. Yes, thanks to JSDelivr minified versions are available with the direct links:
Q. Will you provide LESS/SASS files?
A. Maybe in a future release I'll provide SASS file (with comments).
Q. Do I need the RespondJS polyfill for IE8 like Bootstrap 3 uses?
A. No. Instead the CSS is set to be fixed-width which makes things a lot easier. You don't need to change your HTML markup, the CSS will take care of it as the (min-width:992px) media queries are all set.
Q. Where can I see a demo?
A. Right here: http://coliff.github.io/bootstrap-ie8/test.htm
- View a list of known issues at https://github.com/coliff/bootstrap-ie8/issues
Thanks to BrowserStack for providing the infrastructure that allows us to test in real browsers
