DJ headphones are for cueing the next track and monitoring transitions. Beginner DJs often use them constantly, which slows them down and disconnects them from the room. Here is the actual when-and-when-not framework.

When to use them

When cueing the start of a track. When checking the EQ of the next deck before bringing it in. When the booth monitor is misaligned with the dancefloor and you need to confirm what the crowd actually hears.

When not to

During the actual transition. Once both tracks are playing and the mix is in motion, take the headphones off. You need to hear what the dancefloor hears, not what is in your booth. Most beginner mixes go wrong because the DJ trusts headphone EQ over room EQ.

The half-cup compromise

Many working DJs use single-cup monitoring: one cup on, one cup off. You get the cue signal in one ear and the room signal in the other. The trick is matching what you hear in the room to what your audience hears, in real time.