Support for keyboard multimedia keys have been available in Chrome since v73, released in March 2019.
Firefox will soon let users control songs and videos playing in their browser using the multimedia keys on their keyboards. Official support for multimedia keys will be available in Firefox 81, set for release for late September, later this fall. Firefox 81 will be the first version where Mozilla will turn this feature on, by default; however, Firefox users can also enable it right now, since support for multimedia keys has been secretly available in Firefox since v71, released in December 2019.
