Durability

Just like with regards to their strength, the durability levels of Superman and Thor are relatively similar.

Both characters have survived nuclear bombs going off in their direct proximity, both characters have survived being inside a sun (of course, in Superman’s case, this can actually amp him if it’s a yellow sun) and both have casually shaken off bullets and punches from characters capable of cracking planets.

Feats more unique to each character include Superman surviving the Source Wall exploding near him and Thor absorbing a bomb that was supposed to erase all divinity from the past, present and future.

It’s really hard to split them on this front.

Winner: Tie.