No wizard contemporary to Dumbledore of after his time, till date has been more powerful than him. However, the Great Merlin was the most powerful wizard of all time, equivalent to the God of the wizardkind. The 4 founders of Hogwarts are most likely to have been far more powerful than Dumbledore.
Dumbledore may have been a legendary wizard, but he can't be compared to, well, Merlin, a wizard so legendary even Muggles know of his exploits. Merlin was the world's most famous wizard, and, arguably, the world's most powerful.
Documents in the wizarding world suggest that Merlin was one of the most powerful wizards in Harry Potter and human history in general. Merlin was a Slytherin at Hogwarts and demonstrated an amazing understanding of the magical arts. Some argue him to be the most powerful wizard of all time.
Considered one of the greatest wizard of modern times, Dumbledore is incredibly powerful. The blood oath he had formed with Grindelwald at first prevented him from fighting against him, but we all know that Dumbledore eventually wins, in what is considered the most epic duel of all time in the wizard world.
His exceptional magical abilities, immense knowledge of various branches of magic, and strategic thinking make him a formidable wizard. Dumbledore served as the Headmaster of Hogwarts School of Witchcraft and Wizardry, was a highly skilled duelist, and possessed incredible wisdom and intuition.
1 Voldemort – Harry Potter
He who should not be named makes the number one spot. Voldemort is known for his viciously evil nature. He has wiped out entire generations of Wizards for standing against him, and his power in the dark arts knows no equal.
Since Voldemort wins most of these points, he takes home the title of being the worse warlord of the wizarding world. He was more cunning, naturally talented, feared, and above all powerful, compared to Grindelwald.
1. Albus Dumbledore. Image via Warner Bros.
While Dumbledore is a powerful wizard, Gandalf's innate magical abilities and experience in leadership and diplomacy give him an edge in a battle between the two. While the outcome of a battle between the two would depend on the circumstances, Gandalf would win more often than not.
Even when battling Voldemort, in Harry Potter and the Order of the Phoenix, Dumbledore never uses lethal magic. In the duel, Dumbledore is definitely on par with Voldemort, and Voldemort is seen to be annoyed that he can't overpower Dumbledore.
Albus Dumbledore is the most obvious person who can defeat Voldemort, outside of the Salazar Slytherin vs Voldemort debate, and the Dark Lord seemed to realize it. Rowling herself has explicitly stated in the books that Dumbledore is the only person Voldemort fears and recognizes as a genuine threat to his own power.
Of the characters in the books, the top-tier wizards are pretty clearly shown to be Dumbledore, Voldemort, and Grindelwald. If one accepts that magic has advanced since ancient times, these three are probably even greater than the Hogwarts Founders themselves.
Besides Dumbledore, he is also the only wizard ever known to be able to apparate silently. Voldemort was also said to fear one wizard alone, Dumbledore. In the final book, Voldemort flies unsupported, something that amazes those who see it.
Lord Voldemort (Ralph Fiennes), aka Tom Riddle, was described by Dumbledore as one of the best students ever to graduate Hogwarts as well as "the most dangerous Dark wizard of all time." Before he had even learned about the existence of the Wizarding world, he was terrorizing his fellow orphans with impressive but ...
Although he was intelligent and bookish, Quirinus Quirrell was the weakest of the Hogwarts professors—mostly due to his extremely timid nature.
Without a doubt, the most powerful wizard in Middle-earth is Gandalf the White. While Gandalf was always a reasonably powerful wizard in his own right, facing off against the Balrog in the Mines of Moria, a battle that took ten days and resulted in the mutual demise of Gandalf and the Balrog.
Nope. Dumbledore was widely considered to be the most powerful wizard of his time, if not all time outright. Lord Voldemort was the only wizard who ever rivalled Dumbledore in magical ability. And even though Voldemort could rival Dumbledore, that's all he could do.
He wasn't decisively more powerful than Voldemort. Instead, what makes the focus on Grindelwald so exciting is that he was probably more dangerous than Voldemort -- a notion that has everything to do with his relationship with an unequivocal good guy: Albus Dumbledore.
DUMBLEDORE WAS A BETTER CHARACTER: He Was More Powerful
Throughout the entire franchise, we wanted to see just what Dumbledore was capable of, and boy did he show it... eventually. Snape, while great at making potions, just couldn't compete with Dumbledore in a physical sense, so he loses out on this one.
"Neville's greatest fear was Snape," the post explained. "And for ten months of every year for seven years, he went back and faced that fear over and over and over again. It would be like tossing Ron into a nest of spiders every day.
He may be the titular character, but Harry is far from the most powerful wizard in the wizarding world. Sure, he does eventually go on to take down the greatest dark wizard of all time, but his success comes more as a result of his mother's sacrifice and the support of his friends than it does his own brilliance.