HTMHell: collection of bad (and good) practices in HTML

htmhell.dev

I considered myself pretty up to date with the functionality offered by HTML but HTMLHell show me I was wrong. Notably I discovered the existence of download links (how did I miss that all this time?!) and how to use <picture> for progressive enhancement.

The site has two main section:

  1. Hell: where you find bad, but not obviously bad, examples of HTML code
  2. Heaven: where you discover little-known but very useful features of HTML

There is also an advent calendar with tips and tricks in December. I highly recommend exploring this site if you want to deepen your understanding of what HTML has to offer.