Does my site need to be usable if the CSS and javascript doesn’t load?

Question

I've always wondered this but never really known for sure. Let's say none of my CSS or javascript loads. Do the site still need to be usable? I know a lot of really big sites are useless without CSS and javascript so I'm betting the answer is no but don't know for sure.

Answer

Not necessarily, but there are a few things that you need to make sure of:
  • The page should be using the proper semantic elements. This means things like header, nav, aside, etc.
  • All headings and page content should flow in a logical order. H1 > H2> etc.
  • Without styling, elements should still be in the order they are intended to be read or listened to.