To shorten a song here, upload an MP3 or WAV. Audjust reads the beats and where sections change, then you set the length you want. It cuts from inside the track, not just off the ends, and splices the join on a beat at a section edge so the result sounds like a finished song instead of a chop.
Here's the part worth knowing: cutting from the middle usually sounds better than lopping off the ending. Verses and choruses repeat, so dropping one pass through a verse or one chorus keeps the intro, the hook, and the outro intact, and the seam lands on beat.
That's what makes it work when you need an exact time. A 3-minute track has to run 30 seconds for a reel; a 4-minute song has to fit a 90-second highlight clip. You set the target, and the cut hides inside the music instead of leaving you mid-phrase.
Preview the edit before you download, and try a few lengths if you're not sure which fits. Nothing installs, and there's no account.
If you also need a song to run longer, the same editor extends it to a target length by repeating sections cleanly. Either way, you're changing duration without re-cutting by ear.