Mike Allanson

Understanding Focus in the Browser

It's difficult to implement good a11y for a web app without first understanding focus.

I've practical knowledge of focus and how it works, particularly in relation to DOM events and CSS. I've limited theoretical knowledge about it.


  • What is focus?
  • What (precisely) can be focussed?
  • What are the implications of an element being focussed?
  • Relationship between focus, ARIA attributes and assistive tech like screen readers?

Starting point: html.spec.whatwg.org/multipage/interaction.html#focus