In terms of raw physical power, Superman is far stronger. He has superhuman strength, speed, invulnerability, flight, and various other abilities stemming from Earth's yellow sun.

Batman is a peak-condition human with no superpowers. His strengths lie in intelligence, martial arts mastery, detective skills, wealth, technology, and preparation.

That said, their comic confrontations are more nuanced—Batman has held his own or won encounters by exploiting Superman's vulnerabilities (like kryptonite) or through strategic planning. Writers often frame it as "power vs. preparation."

So it depends on what you mean by "stronger," but purely physical strength goes to Superman by an enormous margin.
