Bootstrap 4.3 introduced Responsive Font Sizes (RFS) which you can enable in the SCSS compiler. If you're compiling the CSS for your project I highly recommend turning it on.
If you're loading Bootstrap from a CDN though you won't be able to take advantage of those RFS rules. This repo offers a quick fix - a tiny CSS file with the relevant changes.
A couple of options are available:
- Copy the CSS rules to your site
- Copy the
bootstrap-rfs.cssrules to your site's CSS - Add the following to your sites
<head>(after loading Bootstrap's) -<link href="bootstrap-rfs.css" rel="stylesheet">
- Use a CDN
- Add the following to your sites
<head>(after loading Bootstrap's) -<link href="https://cdn.jsdelivr.net/gh/coliff/bootstrap-rfs/bootstrap-rfs.css" rel="stylesheet">
Optional: You can add media="screen and (max-width: 1200px)" so it will load the CSS asynchronously. The CSS has the 'max-width: 1200px' media query included as well so this is optional.