Song Key Finder — Identify the Musical Key of Any Song Instantly
Upload an audio file and instantly detect the key, scale, and BPM of any song. Free, no signup required.
Drop your audio file here or click to browse
MP3 · WAV · FLAC · OGG · AAC — Up to 500MB
✓ Free · ✓ No signup · ✓ Detects key, scale & Camelot code
Now find the BPM of this song → Open BPM Finder
Not sure what to do with your key? Use it to find compatible chords, transpose your track, or mix harmonically with the Camelot wheel.
How to find the key of a song
Upload any audio file to the key finder and the tool analyzes the harmonic content using chromagram-based spectral analysis. The key detector correlates pitch class energy against Krumhansl-Kessler key profiles to identify the tonal center. Along with the musical key, the key identifier returns the scale (major or minor), the Camelot code for DJ mixing, and the song key and BPM — all from a single upload.
What is a musical key and why does it matter?
A musical key defines the tonal center of a song — the note that everything resolves to. Songs in C major sound bright and open, while A minor feels darker and more emotional. How do you know what key a song is in? Trained musicians listen for the tonic note, but that's essentially guessing what key a song is in based on feel. A key identifier removes the guesswork by analyzing the actual frequency content. Knowing the key BPM combination lets DJs build harmonic mixes, producers choose compatible samples, and singers find comfortable ranges.
How to use the Camelot wheel for DJ mixing
The Camelot wheel maps all 24 musical keys onto a numbered circle — 1A through 12B. Major keys sit on the B side, minor keys on A. Compatible keys are adjacent: same number, or ±1. For example, 8A (A minor) mixes smoothly with 7A, 9A, or 8B (C major). The key detector in SonicLab outputs both the detected key (e.g., "A minor") and the Camelot code (e.g., "8A") side by side. This song key and BPM data together gives DJs everything needed for harmonic beatmatching in a single step.
How to change the key of a song
Once you know the key, you might want to transpose the song — for example, to match a singer's vocal range or to align with another track's key. Transposition shifts every note up or down by the same interval. You can change the key of a song using a pitch shifter toolor your DAW's built-in transpose function. The process: detect the key → determine how many semitones to shift → apply the transposition. Learning how to change the key of a song is straightforward once you have the detected key as your starting point.
Also find the BPM of a song using our tempo detector. Explore all our free music analysis tools, or read our guide on how to find the key of any song.
Frequently asked questions
What is a song key finder?
A song key finder analyzes an audio file and detects its musical key — the tonal center around which the melody and chords are built. SonicLab's key finder uses chromagram-based spectral analysis to identify the key, scale (major or minor), and Camelot code instantly.
How do I know what key a song is in?
Upload your audio file to the key finder and the tool detects the key automatically. Alternatively, you can identify a key by ear by finding the note that sounds like "home" — but automated detection is faster and more reliable than guessing what key a song is in.
What is the difference between a key and a scale?
A key defines the tonal center of a song (e.g., "C major"), while a scale is the set of notes used within that key. The key tells you where the music resolves; the scale tells you which notes are available. The key finder reports both.
How do I use the detected key for DJ mixing?
Use the Camelot wheel system — songs with the same Camelot code or adjacent codes mix smoothly. SonicLab's key finder outputs both the musical key and the Camelot code so you can match tracks instantly.
Can I find the key and BPM at the same time?
Yes. The key finder detects the musical key, scale, and BPM simultaneously in a single analysis pass. You get all the data you need for mixing, production, or library organization without running separate tools.
What is the Camelot wheel and how does it help DJs?
The Camelot wheel maps all 24 musical keys onto a numbered circle (1A through 12B). Keys that are adjacent on the wheel are harmonically compatible, making transitions smooth. DJs move up, down, or across one number for seamless harmonic mixing.
How do I change the key of a song after finding it?
Use a transposer or pitch-shifting tool to move the song to a new key. For example, shift from C major to D major by raising the pitch by 2 semitones. SonicLab's pitch shifter lets you transpose without affecting tempo.
Is this song key finder free?
Yes. SonicLab's song key finder is completely free — no signup, no account, and no file limits. All audio processing happens locally in your browser, so your files are never uploaded to any server.