The Deluminator was an artefact created by Albus Dumbledore which could take or release light sources from street lights or lamps. It absorbed the nearest light source, and if it was already storing light, it could release it to its original source or another source. It proved useful for subterfuge and protection in particular, such as transporting Harry safely under cover of darkness, or holding private conversations.

Additionally, it could be used to listen in on conversations where the user's name was said. Ron Weasley used it to listen to Harry and Hermione's conversations, and it helped to guide him back to his friends after their falling out. Using it immediately after listening into a conversation allowed the user to Apparate to the location of those speaking.

It can also transport the user and others to a mirror dimension, which Dumbledore utilised in his duel against Credence Barebone in Berlin in 1932.