The overall accessibility of any project built with Bootstrap depends in large part on the author’s markup, additional styling, and scripting they’ve included. However, provided that these have been implemented correctly, it should be perfectly possible to create websites and applications with Bootstrap that fulfill WCAG 2.1 (A/AA/AAA), , and similar accessibility standards and requirements.

    Bootstrap’s styling and layout can be applied to a wide range of markup structures. This documentation aims to provide developers with best practice examples to demonstrate the use of Bootstrap itself and illustrate appropriate semantic markup, including ways in which potential accessibility concerns can be addressed.

    Because Bootstrap’s components are purposely designed to be fairly generic, authors may need to include further ARIA roles and attributes, as well as JavaScript behavior, to more accurately convey the precise nature and functionality of their component. This is usually noted in the documentation.

    Some combinations of colors that currently make up Bootstrap’s default palette—used throughout the framework for things such as button variations, alert variations, form validation indicators—may lead to insufficient color contrast (below the recommended WCAG 2.1 text color contrast ratio of 4.5:1 and the ), particularly when used against a light background. Authors are encouraged to test their specific uses of color and, where necessary, manually modify/extend these default colors to ensure adequate color contrast ratios.

    For visually hidden interactive controls, such as traditional “skip” links, use the .visually-hidden-focusable class. This will ensure that the control becomes visible once focused (for sighted keyboard users). Watch out, compared to the equivalent .sr-only and classes in past versions, Bootstrap 5’s .visually-hidden-focusable is a standalone class, and must not be used in combination with the .visually-hidden class.

    Bootstrap includes support for the prefers-reduced-motion media feature. In browsers/environments that allow the user to specify their preference for reduced motion, most CSS transition effects in Bootstrap (for instance, when a modal dialog is opened or closed, or the sliding animation in carousels) will be disabled, and meaningful animations (such as spinners) will be slowed down.

    Additional resources