Crossfade length is the setting everyone changes first and understands last. The honest answer is that it depends on your format — but the mechanics are worth knowing before you pick a number.
Zero is a real option
Set the crossfade to 0 ms and you get an instant gapless swap. No overlap, no fade, no silence.
For speech-heavy or classical output this is often correct. Crossfading two classical pieces is usually worse than butting them together cleanly.
Where a longer setting bites
Above zero, music-to-music transitions use an equal-power crossfade between the two deck faders — cosine out, sine in — so perceived loudness stays constant through the blend rather than dipping in the middle.
Typical music formats land somewhere between one and three seconds. Longer than that and you start losing the identity of both tracks.
Short items are handled differently
Here is the part worth understanding, because it prevents a real problem.
Consider a 10-second bumper with a 2-second crossfade configured. Naively applied, a fifth of that item is spent handing over — the ident barely establishes before it is being mixed away.
So for short items, roughly under two minutes, the effective overlap is capped relative to track length. A short clip uses a shorter adaptive overlap instead of the full global setting.
Importantly, DJ outro lookahead is not reduced by this cap. When a longer lookahead exists because you set an outro marker, that intent is respected — it is a deliberate mix point, not an accident of a global setting.
Imaging ignores the number anyway
Remember that jingles, voice tracks, commercials and station IDs follow their own transition rules: music fades under them while they hold at unity gain, and they hard-cut into the next music item rather than fading out.
So your crossfade setting mostly governs music-to-music. Imaging is handled by policy, not by the slider.
Where to start
Pick a value, listen to an hour, and pay attention to the joins that sound wrong. Then set outro markers on your power rotation, which fixes far more transitions than adjusting the global number ever will.