classList.js is a cross-browser JavaScript shim that fully implements element.classList. Refer to the MDN page on element.classList for more information.

This works in every browser except IE 7 or earlier.

An older version is hosted at public CDNs, allowing you to use this already small file at nearly zero size overhead. Use one of these URLs:

• //unpkg.com/eligrey-classlist-js-polyfill@1.2.20180112/classList.min.js
• //cdn.jsdelivr.net/npm/eligrey-classlist-js-polyfill@1.2.20180112/classList.min.js

If you would like other versions (such as the current one) hosted there, follow the instructions at https://github.com/jsdelivr/jsdelivr and https://github.com/cdnjs/cdnjs to prepare a pull request.