Song Key & BPM Finder
Upload any song and instantly get its musical key, Camelot code for harmonic mixing, and tempo in BPM. Free. Nothing is stored.
How the key and BPM detection works
This is the same method academic key-detection research uses, running in your browser. First the tool converts your song into a chromagram: it measures how much energy sits on each of the 12 musical pitch classes (C, C#, D and so on) across the whole track. Then it compares that fingerprint against the Krumhansl key profiles, a set of templates from music psychology research that describe how strongly each note tends to appear in every major and minor key. The best match wins. A song that leans hard on A, C and E will score highest against the A minor template, so you get "A minor".
Tempo works differently. The tool builds an onset envelope, a map of where the energy jumps happen in your song, which is where drum hits live. It then checks that map against itself at every possible spacing between 60 and 190 BPM (a technique called autocorrelation) and picks the spacing where the hits line up best. Songs with strong, steady drums detect within 1 to 2 BPM. Ambient tracks with no percussion are harder, and any tool will be less confident on them.
What the Camelot code means
The Camelot wheel renames the 24 musical keys as numbers 1 to 12 with an A (minor) or B (major) suffix, so DJs can mix harmonically without music theory. The rule is simple: from any code, you can mix into the same number, one number up, one number down, or the same number with the opposite letter. A song in 8A (A minor) blends cleanly with 7A, 9A and 8B. Suno creators use it the same way when building playlists or mashups, so tracks flow into each other without clashing.
Why knowing your key and BPM matters
- • Remixing and sampling: pitch-shift and time-stretch tools need the source key and tempo to keep vocals natural.
- • Suno regeneration: put the detected key and BPM in your next prompt to get a track that matches your original.
- • Playlists and DJ sets: harmonic mixing keeps energy up without key clashes between songs.
- • Collaboration: singers and instrumentalists need the key before they can record over your track.
Common questions
What key is my song in?
Upload it above. The tool analyzes the track's chroma (pitch-class) profile against major and minor key templates and returns the best match, for example "A minor", plus its Camelot wheel code (8A, 9B and so on) for DJ harmonic mixing.
How is the BPM detected?
The tool runs onset-based beat tracking on the audio and reports the tempo in beats per minute. It works on any MP3, WAV, M4A, or FLAC, and is most accurate on songs with clear drums.
How accurate is the detection?
Very accurate on music with steady drums and a clear tonal center, which covers most Suno, pop, hip-hop and electronic tracks. Songs with tempo changes, rubato playing, or heavy dissonance can fool any detector, so treat the result as a strong starting point on that material.
Is it free? Do you keep my file?
100% free, no account. The analysis runs entirely in your browser, so your file is never uploaded anywhere. There is nothing for us to store.