BPM Detector and Tap Tempo
Find the tempo of a song or loop in BPM from the audio file, with half and double time and beat lengths in ms, or tap along to count it yourself. No upload.
From a song
Drag a file here, paste it, or choose one. Up to 300 MB. It stays on your device.
Tap tempo
Tap along to the beat — with the button, or Enter or Space while it is focused. Pause for a few seconds to start again.
No taps yet
How is this calculated?
BPM = 60 ÷ beat period in seconds. Tap tempo = 60 000 × (taps − 1) ÷ milliseconds from first to last tap. One beat = 60 000 ÷ BPM ms.Runs in your browser — nothing you enter leaves this device.
About this tool
What it does
BPM Detector finds the tempo of a song or loop, in beats per minute, from the audio file — for DJ sets, setting a delay or a metronome, choosing running music, or matching a loop to a project. Open an MP3, WAV, M4A, OGG or FLAC file and in a moment it shows the tempo to one decimal, how clear the beat was, the half-time and double-time counts, and the length of one beat and one bar of four in milliseconds, which is what delay and reverb settings ask for. It works by measuring how sharply the sound gets louder about 200 times a second — drum hits and note starts stand out — and then finding the time gap at which that pattern best repeats, between 60 and 200 BPM. Any song can be counted at half or double speed, so where both fit almost equally well it prefers the count nearer 120 BPM, the way most listeners tap; both alternatives are shown. Where the beat is not clear — ambient music, rubato piano, speech — it says low confidence rather than guessing. Tap tempo counts it yourself: tap along and it averages the gaps.
How to use it
- Choose or drop a song or loop.
- Read the tempo, its half and double, and the beat length.
- If it says low confidence, or to check it, tap along on the Tap button.
Limits and your data
- Songs whose tempo changes give one average figure; live recordings that drift are rounded to their typical tempo.
- Very fast (over 200 BPM) and very slow (under 60) tempos are reported at double or half: drum and bass at 174 may show as 87.
- Up to the first six minutes are analysed.
- Tap tempo is as accurate as your taps: eight or more taps give a steady figure.
- The file is analysed in this browser tab and never uploaded. Nothing is kept after you leave the page.
Questions
How do I find the BPM of a song?
Open the song file here and read the tempo, or tap along to the beat on the Tap button for at least eight beats.
Why does it show half the BPM I expected?
A beat can be counted at half or double speed and both are correct counts; use the half or double time figure shown with it.
Can it detect BPM from YouTube or Spotify?
No: it reads audio files on your device. For a streamed song, use tap tempo while it plays.
What delay time matches the tempo?
One beat in milliseconds is 60 000 ÷ BPM: 500 ms at 120 BPM. Half of it is an eighth note, a quarter of it a sixteenth.