BPM finder

Find the BPM of a song in three steps

1. Choose a song as an audio or video file, and pick an expected range: auto, 60 to 120, or 90 to 180 BPM.
2. Read the detected BPM, the rounded value, the confidence, and the half-time and double-time alternatives.
3. Press the tap-along button on each beat while the song plays to confirm the number.

How tempo detection works

Beats are moments when new sound arrives: a kick drum, a strummed chord, a hand clap. The tool finds them by measuring spectral flux, which is how much the spectrum grows from one short slice of audio to the next. That gives an onset-strength curve with a spike at every attack. The curve is then compared with delayed copies of itself, a process called autocorrelation. When the delay matches the time between beats, the peaks line up and the score jumps. The strongest delay becomes the tempo, reported to one decimal place and as a rounded number, and how clearly it stands out becomes the confidence.

Half-time, double-time, and the expected range

Tempo is partly a matter of feel. A dubstep track at 140 BPM is often felt at 70, drum and bass at 174 is felt at 87, and a slow ballad might be counted in eighth notes at double speed. The math sees the same pattern at both rates, so the tool shows half and double alternatives next to the main result. If you already know the style, set the expected range. Choose 60 to 120 for hip-hop, ballads, and reggae, or 90 to 180 for house, techno, pop, and drum and bass. Auto picks the most likely value without a hint.

Check it by tapping

Automatic detection is a good first answer, and tapping is a good second opinion. Press the tap-along button on each beat while the song plays and compare your number with the detected one. If yours is half or double, you have found which feel you count in. For music with no file, such as a band rehearsal or a song on the radio, use the tap tempo page instead, which needs nothing but your tapping. DJs use BPM to match tracks in a set, runners use it to build playlists at their running pace, and producers use it to set a project tempo before adding a sample.

When detection fails

Songs with tempo changes, such as live recordings that speed up or tracks with a slow intro, get one average value. Classical music with rubato, ambient pieces, and anything without a clear pulse can produce a low confidence or a meaningless number. Swing and heavy syncopation sometimes push the result toward a related tempo, such as two thirds or one and a half times the real one. When the confidence is low, trust your tapping. Analysis runs in your browser on the decoded audio, so the song is never uploaded, and there is no limit on how many songs you check.