BPM turns a tapped, typed, or detected tempo into timeline markers so you can cut and animate to a beat. It is a free micro tool in Motion Dock.
The round Tap pad sets the tempo. The waveform button finds a tempo from a selected audio layer.
Choose a subdivision, then use Lay grid to write the rhythm into the active composition.
Make the rhythm visible
A grid is a set of ordinary After Effects markers. At 120 BPM, 1/1 places one marker every half second. Downbeats can show bar numbers in a separate color.
You can anchor the grid at the playhead, the range start, or a detected sound. Use evenly spaced beats for a steady rhythm, or detected peaks for individual sound attacks.
Cut and animate to those markers
Snap aligns selected layers. Sequence arranges them along the grid. Split cuts them at marker times. Keys aligns selected keyframes.
These actions read the markers already in the composition. Changing the tempo or subdivision does not move an existing grid. Lay it again to use the new rhythm.
Start with your first beat grid. Each grid or editing action is one After Effects undo step.