The Sorting Hat is described as being very old and patched. When the hat is put on the head of a Hogwarts new arrival, a mouth forms at the brim, and the hat states, for all to hear, which of the four school Houses the child wearing it belongs in: Gryffindor, Hufflepuff, Ravenclaw, or Slytherin.

The Sorting Hat also sings a song for all of the Hogwarts students and staff before the beginning-of-the-year feast, describing its job and the four Hogwarts houses. However, when the wizarding world or the school is in any imminent danger, the hat will also sing about the importance of the four houses standing together as brothers and sisters in the fight against evil. It is clear that the Hat has some level of consciousness; we hear that its song is different every year, and that its song reflects the need to deal with threats against Hogwarts.

The Sorting Hat's unusual qualities are due to the fact that Godric Gryffindor, one of the four Hogwarts founders, owned the hat, and knowing that he would not be around to select houses for the incoming students forever, placed a charm on it to do its job.The Sorting Hat has an affinity for the Sword of Gryffindor, as it has produced the sword twice now; possibly this affinity comes from the fact that both were the property of Godric Gryffindor, and he may have established that particular affinity himself. It also seems the Hat is capable of summoning the Sword from anywhere.