A song key finder tells you which key a song is in. Open an MP3 or any audio file, or press Live and let it listen to a song, your singing or humming. In a few seconds you see the key (major or minor), how sure the result is, the relative key, the tempo and the tuning. Nothing is uploaded.
[opc-song-key-finder]
Related tools
How to find the key of a song
- Open the song or press Live. Open a song reads MP3, M4A, WAV, OGG, FLAC or the sound of an MP4 video. Live is a live key finder: play the song on a speaker, or sing or hum a verse near the microphone.
- Read the key. You see the key (for example Eâ™ major), a confidence score, the relative key, the key signature and the scale notes, plus the tempo and the tuning.
- Check doubtful results. Below 70 % confidence, the three next-best keys are listed.
- Next step. Change this key opens the key changer; Key for your voice helps you pick your best key.
More options: analyse only a section (for songs that change key) and Camelot / Open Key codes for DJs.
How key detection works
The finder measures which of the 12 notes sound most, then compares that pattern with all 24 keys. Every note, in any octave, is folded into one of 12 pitch classes (C, C♯, D … B). This chroma profile shows how much of each note the song uses. Overtones are removed first, so a loud bass C does not count as a G.
Each key has a typical shape: the home note, its fifth and its third sound most, notes outside the scale least. Music psychologists measured these key profiles (Krumhansl and Kessler, Temperley, Albrecht and Shanahan); the tool compares the song with all three and picks the best match. It first measures the tuning against A4 = 440 Hz, so a band tuned to 442 Hz is still read correctly. The tempo comes from the rhythm of the note onsets.
The guide to what a song key is explains keys from the start; the circle of fifths shows how the 24 keys are related.
| What we tested | Result |
|---|---|
| 24 test songs, one per major and minor key | 24 of 24 correct, confidence 84–99 % |
| 4 songs with drums and bass | Key and tempo correct in all 4 |
| Real recordings: Bach (C major), Für Elise (A minor) | Both correct; tuned at A4 = 442–443 Hz |
| Humming with vibrato (D major, E minor) | Both correct |
| Live: a song in A minor and a hummed tune, through a microphone | Right key after 8 s |
| A song that changes key (C major, then E major) | Low confidence overall; each half correct as a section |
Why relative major and minor keys get confused
A major key and its relative minor use the same seven notes: C major and A minor are both the white keys of a piano. Only the home note differs. Detectors, and people, mix them up when a song hovers between the two chords. The finder checks the first and last chords to decide; if it is still close, the other key appears under Other possible keys.
| Confusion | Example | How to decide by ear |
|---|---|---|
| Relative key | C major ↔ A minor | Which chord feels like the end of the song: C (bright) or Am (dark)? |
| Neighbour key (one note differs) | C major ↔ G major or F major | Listen for F♯ (then G major) or B♠(then F major) |
| Parallel key (same home note) | C major ↔ C minor | Is the third note of the scale E (major) or E♠(minor)? |
| A semitone off | D major ↔ D♠major | Old recordings drift: a Pachelbel Canon we tested plays 19 cents flat, in D♠major, not the D major of the score |
How to find the key of a song by ear or from the chords
- Find the home note. Hum along and stop on the note that feels finished; find it on a piano or with the vocal range test.
- Major or minor? A bright third above the home note means major; a dark one means minor.
- Check the chords. The first and last chord are usually the key, and most other chords belong to its scale.
- Read the key signature on sheet music: its sharps or flats give a major key and its relative minor; the last chord decides.
The step-by-step guide on how to find the key of a song has worked examples for guitar and piano.
Camelot and Open Key for DJs
DJs mix tracks whose keys fit, and the Camelot wheel numbers the keys for that. Turn on Camelot + Open Key under More options to see both codes. Tracks with the same number mix cleanly, and so do tracks one number apart (8A to 9A) or with the other letter (8A to 8B, the relative key). Open Key is the same wheel starting at C major = 1d.
| Number | Minor (A) | Major (B) | Open Key |
|---|---|---|---|
| 1 | G♯ minor (1A) | B major (1B) | 6d / 6m |
| 2 | E♠minor (2A) | F♯ major (2B) | 7d / 7m |
| 3 | Bâ™ minor (3A) | Dâ™ major (3B) | 8d / 8m |
| 4 | F minor (4A) | Aâ™ major (4B) | 9d / 9m |
| 5 | C minor (5A) | Eâ™ major (5B) | 10d / 10m |
| 6 | G minor (6A) | Bâ™ major (6B) | 11d / 11m |
| 7 | D minor (7A) | F major (7B) | 12d / 12m |
| 8 | A minor (8A) | C major (8B) | 1d / 1m |
| 9 | E minor (9A) | G major (9B) | 2d / 2m |
| 10 | B minor (10A) | D major (10B) | 3d / 3m |
| 11 | F♯ minor (11A) | A major (11B) | 4d / 4m |
| 12 | C♯ minor (12A) | E major (12B) | 5d / 5m |
Want two tracks in the same key? Measure the gap with the semitones between keys chart, then shift one with the pitch shifter or, to change the tempo as well, the pitch and tempo changer.
Which tool should you use?
| Tool | Use it when | Result |
|---|---|---|
| Song key finder (this page) | You want to know the key, tempo or tuning of a song | Key, confidence, BPM |
| Online key changer | You know the key and want the song in another one | MP3 or WAV |
| Audio pitch changer | Any audio file, shifted by semitones and cents | MP3 or WAV |
| Vocal pitch changer | Your own recorded voice, higher or deeper | MP3 or WAV |
| Transpose music online | You have chords or a chord sheet, not a recording | Chords in the new key |
| Key for your vocal range | You know your range and want the best key to sing in | Guide |
Questions about finding the key of a song
What key is this song in?
Open the song in the finder above, or press Live and play it near your phone. The key appears in a few seconds with a confidence score. Below 70 %, compare the other keys listed and check the last chord by ear.
Can it find the key from my voice?
Yes. Press Live and sing or hum a whole verse or chorus. One voice gives fewer notes than a band, so 15 to 30 seconds works best. It tells you the key you are singing in, not your vocal range.
How accurate is the key finder?
On clear music it found every key we tested, including real recordings and humming. It is less sure with drums only, speech, heavy noise, or songs that change key. The confidence score says so.
Can I find the key of a song on YouTube or Spotify?
Yes, with Live. Play the song on one device and let the finder listen on another, or on the same device with the speaker turned up. Streaming files cannot be opened directly. To sing along in another key, use the YouTube pitch changer.
Is my song uploaded?
No. Files and the microphone sound are analysed in your browser on your device, and nothing is saved. It is free, with no sign-up.
Tested: what we measured
- 24 test songs, one per key: 24 of 24 correct, relative key right in all 24.
- Real recordings and songs with drums: 7 of 7 keys correct, tempo within 1 BPM.
- Camelot and Open Key codes of all 24 keys match the published wheels.
Last updated 27 September 2026 by Mayer. More tools on the online pitch changer home page; how we test: how it works.