@chriscoyier @csswizardry @frontzurich @css This spurred some quick Googling research

Using preconnect and dns-prefetch is redundant. preconnect will do the DNS lookup + connection stuff

But IE doesn’t support preconnect so dns-prefetch is a fallback there.

caniuse.com/#feat=link-rel-preco…
caniuse.com/#feat=link-rel-dns-p…