Song Key Finder
Drop an audio file to detect its musical key and scale. The analysis runs on your device; nothing is uploaded.
How the key detector works
Three steps, all inside your browser
1. Drop an audio or video file
MP3, WAV, FLAC, AAC, OGG, M4A, MP4 and WebM are decoded by your browser. The file never leaves your device.
2. Pitch-class profile
The analyzer measures how much energy falls on each of the 12 pitch classes across the whole track, then compares that profile with the 24 key templates.
3. Key, scale and Camelot code
You get the best-matching key and scale, how clearly it wins over the runner-up, the relative key and the Camelot position for harmonic mixing.
What the Camelot code means
The Camelot wheel renumbers the 24 keys as 1 to 12 with A for minor and B for major, so DJs can read key compatibility without music theory. Two tracks mix cleanly when their codes are equal, one number apart with the same letter (8A → 9A), or the same number with the other letter (8A → 8B, the relative major). Moving two steps or more usually clashes.
Relative keys and transposing
Every major key shares its notes with one minor key: C major and A minor, G major and E minor, and so on. If a song is in a key that is hard to sing or play, the relative key keeps the same notes while changing the mood; a capo or a transpose setting moves the whole song to a more comfortable key.
Camelot wheel
| Camelot | minor (A) | major (B) |
|---|---|---|
| 1 | 1A · G# minor | 1B · B major |
| 2 | 2A · Eb minor | 2B · F# major |
| 3 | 3A · Bb minor | 3B · Db major |
| 4 | 4A · F minor | 4B · Ab major |
| 5 | 5A · C minor | 5B · Eb major |
| 6 | 6A · G minor | 6B · Bb major |
| 7 | 7A · D minor | 7B · F major |
| 8 | 8A · A minor | 8B · C major |
| 9 | 9A · E minor | 9B · G major |
| 10 | 10A · B minor | 10B · D major |
| 11 | 11A · F# minor | 11B · A major |
| 12 | 12A · C# minor | 12B · E major |
Who uses a song key finder
DJs building harmonic sets
Read the Camelot code of every track in your crate and move around the wheel one step at a time for mixes that stay in tune.
Singers and karaoke
Check the key of the original before choosing a backing track or asking the band to transpose.
Producers sampling and remixing
Match a sample to your project key before chopping it, or pick a vocal that sits in the relative key of your beat.
Learning a song by ear
Knowing the key narrows the chords you are listening for from twelve to a handful.
Song key finder FAQ
Accuracy, limits and how it fits with the rest of AHA Music
How accurate is the key detection?
For music with a stable tonal centre (pop, rock, house, hip-hop, acoustic) the detected key is usually right; the most common miss is the relative major or minor, which is shown next to the result for that reason. Drum-heavy intros, modulating songs and atonal music lower the confidence score.
What does the confidence score mean?
It compares how strongly the audio matches the winning key against the runner-up. A high score means one clear tonal centre; a low score means several keys fit almost equally well, so trust the result less and try a clip with the chorus.
Can it detect key changes in the middle of a song?
No. The analyzer reports the single key that fits the whole file best. If a song modulates, cut the section you care about (the first 60 seconds, or the chorus) and analyze that clip on its own.
Does my file get uploaded?
No. The file is decoded and analyzed by your browser. Nothing is sent to AHA Music's servers, which also means there is no limit on how many files you analyze.
Which formats and sizes work?
Any audio or video your browser can decode: MP3, WAV, FLAC, AAC, OGG, M4A, MP4 and WebM. Very long files take longer because the whole track is decoded in memory; a 3 to 5 minute song takes a few seconds.
What is the difference between this and the BPM & Key Finder?
The BPM & Key Finder reports tempo, key, mood, energy, loudness and danceability in one pass. This page focuses on the key alone and adds the Camelot code, the relative key and the confidence score. Both run on your device.
Can I find out which song it is as well?
Yes. After the analysis, use "Identify this song" to send the same file to the song finder, which matches it against ACRCloud's catalogue of more than 100 million tracks and returns the title, artist and streaming links.
Is the key detector free?
Yes, free and unlimited, with ads. Pro removes ads across the site.