BPM Finder
Measure the tempo of any audio file to one decimal place, with the key alongside it. The file is read by your browser and never uploaded.
What it does
Measured from the audio, not looked up
Most BPM sites are catalogues: you search a title and get whatever tempo somebody entered for that release. Convenient for a chart single, useless for your own bounce, a live version, an edit, or anything not in the database — and quietly wrong when the version you have is not the version they listed.
This measures the file. The track is cut into short frames, the moments where something gets suddenly louder are picked out, and that pattern of accents is compared against itself at every plausible spacing. The spacing that lines up best is the beat, and the tempo falls out of it — one number, one decimal place, from your actual audio.
It also reports the key, because almost everyone who wants the BPM wants that too. And it tells you the half-time and double-time readings, which is the one thing tempo detection genuinely cannot resolve on its own: a track at 140 with a slow backbeat is mathematically identical to one at 70 with busy hats. Your ear settles that in a second; an algorithm cannot.
How it works
How to find the BPM of a song
Choose a file, read the number. A few seconds, no sign-in.
- 1
Choose the audio file
MP3, WAV, FLAC, M4A or a video file. It is decoded in the page and stays on your device.
- 2
The beat pattern is measured
The whole track is analysed rather than a sample of it, so a tempo that only settles after the intro still comes out right.
- 3
Read the tempo, and the alternatives
You get the BPM, a confidence score, the half-time and double-time readings, and the key from the same pass.
What you get
What an accurate BPM finder has to handle
Half-time and double-time, shown rather than guessed
Every tempo detector faces this ambiguity and most quietly pick one. Both readings are listed, because which one is "the" tempo is a musical judgement rather than a measurement.
More precise than tapping along
A tap tempo tool measures your reaction time as much as the music, and lands within a couple of BPM at best. Measuring the waveform gives the same answer every time, to a decimal.
- ±2 BPM at best
- needs 20 seconds
- your reaction time counts
- one decimal place
- whole track, not a guess
- repeatable
A song BPM finder that works on any file
Your own mix, an unreleased edit, a rehearsal recording, a track with no metadata at all. Nothing needs to exist in a catalogue for this to work.
Free, with nothing uploaded
The analysis runs in your browser. There is no account, no credit cost and no cap on how many tracks you check — and the audio never reaches a server.
Who uses it
When the tempo is the thing you need
Beatmatching a set
Knowing every track’s tempo before you play it is what makes a transition planned rather than lucky.
Setting a project tempo
Get the BPM of the reference or the sample first, then start the session at that number so nothing has to be stretched later.
Building a running or workout playlist
Cadence is tempo. Sorting tracks by BPM is the difference between a playlist that carries you and one that fights you.
Syncing video to music
Cut on the beat by working out the frame interval from the BPM instead of nudging clips by eye.
Practising to a click
Set the metronome to the recording rather than to a round number somebody assumed.
Tagging your own library
Run your exports through and write the tempo into the filename, so you never have to work it out twice.
FAQ
BPM finder questions
