Without kryptonite, Superman wins instantly. With it, Batman has a shot — and he's proven it.
The most iconic matchup in DC history, and one that's been definitively explored in both comics (The Dark Knight Returns) and film (BvS). The answer always comes back to one thing: kryptonite.
Without kryptonite, this fight lasts exactly as long as Superman wants it to. He's faster, stronger, more durable, and can project enough energy to level continents. Batman is a peak-human in a bat-themed suit. The matchup is absurd on paper.
But Batman is the best-prepared hero in fiction. He has dedicated contingency plans for defeating every member of the Justice League, including Superman. Given kryptonite, a power-dampening suit, and preparation time, Batman has canonically fought Superman to a standstill multiple times.
The deeper question this matchup poses is: is 'preparation' a fair power in a hypothetical fight? If yes, Batman is one of the most dangerous characters in fiction. If we're talking about a random encounter with no prep? Superman wins before Bruce finishes reaching for his utility belt.
Batman's contingency plans for Superman are legendary and have worked in multiple canonical encounters. Kryptonite-laced armor, red sun grenades, and power-dampening technology can reduce Superman to near-human levels. Batman's psychological warfare — he knows Clark personally — is a devastating tool.
Superman can end this in a femtosecond with heat vision or a speed blitz. Without kryptonite, Batman has literally zero chance. Even WITH kryptonite, Superman can attack from orbit, use freeze breath from a mile away, or simply outlast the kryptonite's effect. Superman holds back against Batman out of respect — if he didn't, there would be no fight.
Superman wins in any scenario where Batman doesn't have specific prep with kryptonite. With full preparation, Batman can absolutely compete — he's proven it. But in the 'random encounter' scenario, Superman's overwhelming physical superiority makes this a non-contest.
Batman also fights
Superman also fights