Superman may be considered a god among men in the DC Universe, but how does his strength measure up against Marvel Comics’ God of Thunder Thor? It’s a challenging question that fans can debate over until Ragnarök, but the comics do offer some fantastic feats of strength that offer some hints as to how these heroes’ strength levels compare to each other.
Keep in mind that both Thor and Superman have had varying power levels over the years as well as multiple ways of further enhancing their strength. Thus, even though these two have met in various Marvel/DC crossovers over the years, any past meetings don’t necessarily show either hero at their peak, leaving the question of which hero is stronger up for debate.
While the answer may seem straightforward based on their ridiculously high-level power feats, it gets murkier when looking at some of the finer points in their powers. In terms of the power to lift and move large objects, Superman has a stronger edge against Thor. Thor may have been able to move objects that weigh as much as planets, but the Silver Age Superman not only pushed actual planets out of orbit all the time, but even went so far as to move entire galaxies on a whim. The modern age Superman shows that his power is basically limitless as he considered bench pressing the Earth for five days hardly a workout.
It’s also worth noting that while Thor may gain power from Earth and Asgard, Superman can gain power from multiple suns – not just Earth’s. Indeed, the Last Son of Krypton could potentially supercharge himself with greater strength by visiting multiple planets with yellow or blue suns, while the God of Thunder can only draw power from two realms and enhance his strength primarily with Asgardian artifacts. To top it off, Superman can gain additional power from Thor’s own hammer, giving him a clear edge in power sources.
Things get a bit stickier, however, when one considers how well a Superman at his peak would fare against a maximum-powered Thor in a no-holds-barred fight. The JLA/Avengers crossover gave the win to Superman, but it would be interesting to see how the two would fare at each other if they were both at their greatest level of power.
After all, Superman has shown he has a vulnerability against magic, and while the question of whether Asgardians use science or sorcery (or some combination of both) is debatable, it’s possible that Superman would be more vulnerable against Thor’s power if magic was a factor and Thor was using every Asgardian magical tool he had at his disposal and the Odin-Force. Clark might get more strength from Mjolnir, but if all that power was ever turned against him, it might not be so beneficial. The odds are still in Superman's favor - but Thor would definitely make him work for a victory.
As a side note, it's also worth pointing out that Superman has shown he can lose his strength in many different ways. Aside from exposure to Kryptonite, Superman’s powers fade completely under the light of a red sun and can be robbed by magic. Notably, even when Superman is at his most powerful, he can be rendered temporarily mortal thanks to red sun rays or a magic attack (although he usually gets back up to full strength very quickly). Thor, by contrast, tends to lose his power only with very specific magical spells. Odin once rendered Thor mortal by transforming him into the human Doctor Donald Blake (and arranged it so that he would lose his godly power if separated from his hammer for more than sixty seconds). While this certainly gave Thor an Achilles’ Heel (which he eventually lost), he’s less likely to lose his power in a fight due to his lower number of vulnerabilities.
Even so, taking both heroes at their maximum potential, it’s practically a given that Superman would overpower Thor in terms of sheer physical strength. He may not consider himself a god, but the Last Son of Krypton can still outmatch the God of Thunder on his best day.