Key & BPM Finder
Tap the tempo by ear, or drop in a track to detect its key, Camelot code, and BPM. Everything runs right here in your browser, your audio never leaves your device.
Tap the circle or hit Space in time with the beat
100% local. Analysis runs entirely in your browser using WebAssembly, your file is never sent to a server or used to train anything. The same principle behind Xport Studio.
How to find the key and BPM of a song
- Open the Analyze a file tab and drop in a track, or use Tap tempo to tap the beat by hand.
- The tool reads the audio in your browser and shows the musical key, its Camelot code, and the BPM.
- If the tempo looks doubled or halved, tap the ÷2 or ×2 button to fix the octave.
- Copy the result, or use it to tag and sort your library.
What the key, Camelot code, and BPM tell you
The key is the note a song resolves to and the scale built on it, such as A minor or E-flat major. The Camelot code is the same information written the way DJs use it: a number from 1 to 12 and a letter, A for minor keys and B for major, so A minor reads 8A and C major reads 8B. BPM, beats per minute, is the tempo.
Each number has a job. DJs use the key and Camelot code to mix tracks that blend harmonically, and the BPM to beatmatch them. Producers set their project tempo from the BPM and choose samples in a compatible key. Singers use the key to decide whether a song needs moving into their range, which the Transpose Audio tool can do. Anyone sampling or remixing a track needs both numbers before they start.
Why the BPM sometimes comes out halved or doubled
Tempo has an octave problem. A trap beat at 140 BPM often feels like 70 because the snare lands half as often as you expect, and drum and bass at 174 can be counted as 87. Neither reading is wrong. The pulse is genuinely ambiguous, and any analyzer can land on either one.
That is what the divide by 2 and times 2 buttons are for. If the number feels too slow or too fast for what you hear, flip it. Genre is a good guide: house usually sits between 120 and 130 BPM, and drum and bass between 170 and 175. For a live recording with a drifting tempo, the result is an average across the track.
How accurate is it, honestly
The analysis uses essentia, an open-source audio analysis library from the Music Technology Group at Universitat Pompeu Fabra in Barcelona, running in your browser through WebAssembly. The key comes from its key extractor and the tempo from its BPM estimator. On most produced music with a clear tonal center and a steady beat, the results are strong.
Some material is genuinely hard. Songs that change key, modal or ambient pieces, and live recordings played without a click can all confuse a key detector. The most common disagreement is between relative keys, such as A minor and C major, which share every note, so an analyzer can pick either. The Camelot code keeps that useful, because relatives share a number and mix together anyway. Drum-only loops have a tempo but no real key, so trust the BPM there and ignore the key.
Finding the key and BPM of a song you can only stream
The analyzer needs an audio file. For a song you only have on a streaming service, two routes work. For the BPM, use the Tap tempo tab while it plays, or the standalone Tap Tempo Live BPM Detector page with its bigger button. For the key as well, capture what a browser tab is playing with the Audio Screen Recorder, which saves a WAV you can drop straight in here.
Once you have a track’s Camelot code, the Camelot Wheel shows which keys mix cleanly with it, so you can plan the next song in a set.
More tools for key and tempo
FAQ
Is my audio uploaded anywhere?
No. Detection runs entirely in your browser with WebAssembly, so your file never leaves your device and we never see it.
How accurate is the key and BPM detection?
It uses essentia, a respected open-source audio analysis library. Results are strong on most produced music with a steady beat and a clear key. Songs that change key, ambient pieces, and live recordings are harder, which is why Tap tempo and the halve and double buttons exist.
What is a Camelot code?
It is the notation DJs use for harmonic mixing: a number from 1 to 12 plus a letter, A for minor and B for major. Tracks with the same code, the same number, or a number one step away usually mix cleanly. The Camelot Wheel shows the full chart.
Why does it say C major when the song sounds like A minor?
A minor and C major are relative keys that share exactly the same notes, so a detector can land on either. They share a Camelot number (8A and 8B), so for mixing it makes no difference; for playing along, trust your ear on which one feels like home.
Why is the BPM half or double what I expected?
The same groove can be counted at two tempos, for example 70 or 140. Press the divide by 2 or times 2 button to switch to the reading that matches how the song feels.
How do I find the key and BPM of a song I can only stream?
Use the Live BPM Detector, which listens to the tab or your mic while it plays, or tap along in the Tap tempo tab. For the key too, record the browser tab with the Audio Screen Recorder, then drop the WAV in here.
Does it work on acapellas and stems?
Yes. Harmonic stems such as chords, bass, or pads usually give a clear key. A bare vocal can work but gives the detector less to go on, and a drum stem gives a tempo but no meaningful key.
Which file types work?
MP3, WAV, FLAC, M4A, OGG, and AAC.
Is it free?
Yes, completely free, with no sign-up and no limit on how many songs you analyze.