How to make Bootstrap 4 compatible with IE9 and IE10

Question

Which polyfill libaries can be used to make Bootstrap 4 (or most of Bootstrap 4) work with IE9?

I've come across these libraries:

• https://github.com/jonathantneal/flexibility
• https://github.com/coliff/bootstrap-ie8

Thanks.

Answer 1

Looking at their website they recommend using Bootstrap 3 for IE8-9 support.

If you require IE8-9 support, use Bootstrap 3. It’s the most stable version of our code and is still supported by our team for critical bugfixes and documentation changes. However, no new features will be added to it.

The reason that it is hard to support bootstrap 4 with IE9 and IE10 is that is uses modern css ( flexbox ) and html5 elements. They do not provide fallbacks in their css so you would have to manually add those fallbacks.

Please be aware that some CSS3 properties and HTML5 elements are not fully supported in IE10, or require prefixed properties for full functionality

How you can fix Bootstrap 4 for IE9 and IE10:

• Autoprefixer allows you to create fallbacks based on browser support. This won't fix all of your problems however.
• HTML 5 shiv a HTML 5 fallback for legacy ie browsers
• Anywhere flexbox is used will need a float based fallback

You linked above to the open source project Bootstrap IE8 this is probably your best option as it's built to solve your problem.