What BPM and key tell you
BPM is beats per minute: how fast the pulse moves. Key is the tonal home of a track: the note and scale everything else leans toward. Together they decide whether two pieces of music can sit on top of each other without a fight.
The Camelot code is the same key written for DJs. Minor keys end in A, major keys end in B. Matching numbers, or numbers one step apart, blend cleanly. 8A (A minor) sits next to 7A, 9A and 8B.
Why key matters for sampling and mixing
Flip a sample in the wrong key and every melody you add on top clashes with it. Find the key first, then tune your 808, write in the same scale, or pitch the sample to fit the record.
In a DJ set or a mix, key decides whether a transition feels intentional or sour. Tempo you can stretch. A key clash you can hear from the back of the room.
How to use the result
Set your DAW tempo to the BPM shown. If the groove feels wrong, try the half-time or double-time value. Trap sits around 130 to 160 but is often felt at half that, and detectors can land on either.
Then load a scale or a key-locked instrument in the detected key. If a melody still sounds off, try the relative key. Relative major and minor share the same notes, and the strongest note in the track decides which one is home.
How it works
Your browser decodes the file and analyzes it locally. Tempo comes from beat detection on the central part of the track. Key comes from the energy in each of the 12 pitch classes, compared against the 24 major and minor key profiles. Nothing is uploaded, which also means it works on unreleased music you would not hand to an upload site.
It is an estimate. Songs that change key, sit between modes, or have no steady drums will give weaker results. For a deeper walkthrough of tapping BPM by ear and checking key, read how to find the BPM and key of a song.
Questions
Is this BPM and key finder free?
Yes. There is no account, no upload and no limit on how many files you check.
Is my audio uploaded anywhere?
No. The file is decoded and analyzed inside your browser tab. It is never sent to a server.
Why does the BPM look half or double what I expected?
Beat detectors can lock onto the half-time or double-time pulse, which is common in trap. The tool shows both alternatives so you can pick the one that matches what you hear.
What is a Camelot code?
The Camelot wheel numbers the 24 keys from 1 to 12, with A for minor and B for major. Keys with the same number, or a number one step away, usually mix together cleanly.