How to find the BPM and key of a song
- Drop your audio file on the box above, or tap it to pick a file from your phone or computer.
- Wait a few seconds while your browser listens to the track (it analyzes up to the first 5 minutes).
- Read the tempo in BPM and the key with its Camelot code. If the tempo feels twice as fast or slow, use the half/double values shown.
What it is good for
DJs use it to plan harmonic mixes, producers to match samples and acapellas to a project tempo, and musicians to find the key before learning a song or setting up a backing track.
Frequently asked questions
How accurate is the BPM finder?
On our test set of 14 tracks with a known tempo, it was within 1 BPM on 13 and gave exactly half the tempo on the 14th (a 174 BPM drum & bass track read as 87). Songs with a steady beat are the most reliable; live recordings with tempo changes give an average.
How accurate is the key detection?
On 18 labelled tracks it named the exact key on 11. Every miss was a closely related key: the relative major/minor (such as C major vs A minor, which share the same notes) or a key a fifth away. That is why we also show a second guess and the Camelot code.
Is my song uploaded anywhere?
No. The file is decoded and analyzed by your own browser using the Web Audio API. Nothing is sent to a server, so it works with unreleased music and even offline once the page has loaded.
What is the Camelot code?
It is the DJ notation for keys (for example 8A = A minor, 8B = C major). Tracks with the same number, or a number one step away, usually mix together without clashing.
Why does it say half or double the BPM I expected?
Tempo can be heard at two speeds: a 140 BPM track can feel like 70. The tool picks the most likely one and shows half and double underneath, so you can choose the one that matches how you count it.
MP3 encoding uses LAME (lame.sourceforge.io, LGPL) via lamejs. Your files are processed on your device and never uploaded.