Detect the musical key and scale of any track in seconds. Free browser-based key finder for DJs, producers, and musicians.
100% in-browserNo uploadFiles ≤ 50 MB
Loading tool…
Key features
Instant results
Decoded and processed locally with the Web Audio API — most jobs finish in under a second.
Private by design
Your file never leaves the browser. No upload, no server, no tracking.
Free & unlimited
No sign-up, no daily caps, no watermark. Just open and use.
How to use the Key Finder
1
Upload your audio file — any format your browser can play, up to 50MB.
2
The Krumhansl-Schmuckler algorithm estimates the key and scale automatically.
3
Read the key, the Camelot number for DJing, and see it highlighted on the circle of fifths.
What is a musical key?
A key is the tonal center of a song: the note and scale that its melody and harmony revolve around. A track in C major uses the notes of the C major scale and gravitates home to C. Major keys generally sound bright; minor keys generally sound darker — though context and arrangement matter as much as the key itself.
Key is not the same as tempo or time signature: a song's key describes pitch relationships, not rhythm. Two songs in the same key can have completely different grooves, and a DJ can still mix them harmonically even at different BPMs (with pitch/tempo lock).
Musical key vs BPM: what's the difference?
BPM measures how fast beats occur; key measures which pitches dominate. Both matter for mixing: BPM decides whether two tracks can share a rhythm, key decides whether their melodies and basslines agree when layered. The best transitions usually satisfy both.
Harmonic mixing with the Camelot wheel
The Camelot system labels every key with a number and letter (e.g. 8B for C major, 8A for A minor). Tracks mix most smoothly when their codes match, are ±1 on the number, or share the same number with A↔B swapped (relative major/minor). Our result card shows the Camelot code next to the detected key so you can plan mixes without memorizing music theory.
How this detector works
The analyzer computes a chromagram — how much energy each of the 12 pitch classes receives across the track — then correlates it with the Krumhansl-Schmuckler perceptual profiles for all 24 major and minor keys. The best-scoring key wins. Heavily modulating songs (multiple key changes) report their most prominent key.
Frequently asked questions
What key is this song in? How do I find out?
Upload the track to this key finder and the key and scale are detected automatically in seconds — no ear training required. You also get the Camelot code for harmonic DJ mixing, plus the confidence rating so you know when to double-check by ear.
How do I know what key a song is in by ear?
Hum the note that feels like 'home' at the end of the chorus, then find it on a keyboard — that's usually the tonic. Major scales sound bright, minor scales darker. Algorithmic detection like this tool applies the same logic with a chromagram and Krumhansl-Schmuckler profiles, which is faster and more consistent for most people.
Is key detection always correct?
On clearly tonal music (pop, EDM, hip-hop, rock) it is right most of the time, but no algorithm — or human — is 100% certain on ambiguous or heavily modulating tracks. Use the confidence indicator: for anything you'll release or mix in public, verify by ear against the tonic.
What's the difference between C♯ and D♭?
They're the same pitches (enharmonic equivalents) but different keys in notation. Detection reports sharp spellings; the Camelot number is identical either way, so harmonic mixing is unaffected.
Can I shift a song to another key after finding it?
Yes — use our free Pitch Shifter to transpose by semitones. Shifting by +1 semitone moves from, say, C major to C♯ major while keeping the tempo and duration intact.