DJ Harmonic Mixing
DJs check each track's key and pick neighbours that blend.
Examples
- Key-matched transitions
- Mashup key checks
How This Key Finder Works Out a Song's Key
A key finder, or song key finder, tells you which key a song is in, such as C major or A minor. This one decodes your file in the browser, measures how strongly each of the 12 notes sounds, and compares that pattern with major and minor profiles to pick one of 24 keys. Nothing leaves your device.
What the Key Finder Shows
The key first, then the notes that belong to it and the keys that sit beside it.
Key, Major or Minor, and Scale Notes
The key finder names the key, says major or minor, shows a confidence percentage and lists the seven scale notes.
Key Features
24 Keys
12 major, 12 minor
Scale Notes
All seven shown
Confidence
A rough score
Why Use This Key Finder
A free key finder for song files.
01Key
24 Keys Covered
This key detector picks one of 12 major and 12 minor keys from the notes in your file.
02Scale
Scale Notes Listed
Every note of the detected scale, handy for writing or improvising.
03Related
Three Neighbouring Keys
Relative key, fifth up and fourth up.
04Private
Stays on Your Device
Analysis runs in your browser. Your file is not uploaded.
05Limits
Files Up to 80 MB
Up to 5 minutes on desktop and 2 minutes on mobile.
06Free
Free Key Finder Online
No sign-up, no credits. A Bach prelude sample is built in.
Who Uses a Key Finder
Anyone who needs to know what key a song is in.
Producers Layering Samples
Producers find a sample's key before layering it.
Examples
- Matching a sample key
- Checking a vocal chop
Singers and Players
Singers and players find a cover song's key and where to transpose.
Examples
- Picking a comfortable key
- Jam session prep
Students and Teachers
Students check ear-training answers against a detected key.
Examples
- Ear-training checks
- Scale practice
Find a Song's Key in Three Steps
Choose a file, press one button, read the key.
- 1Step
Choose a File
Drop an audio file on the page or browse for one, up to 80 MB.
- 2Step
Press Find Key
The file is decoded and its notes measured in your browser.
- 3Step
Read the Result
You get the key, a confidence percentage, scale notes and related keys.
Key Finder FAQ
Answers about finding a song's key with this key finder.
How do I find what key a song is in?
Choose the file and the key finder shows its key, such as G major or A minor, with scale notes, three related keys and a confidence percentage.
How does this key finder pick a key?
The key finder measures how strongly each of the 12 notes sounds, then scores that pattern against major and minor profiles. The closest of the 24 keys is shown.
What does the confidence percentage mean?
The confidence percentage blends how well the best key fits with how far it leads the runner-up. It is a rough score, not a probability, so check a low one by ear.
Why does the key finder say C# when my chart says Db?
Black-key notes are always spelled C#, Eb, F#, Ab and Bb, so Db major shows as C# major and G# minor as Ab minor. The notes are the same.
What if the key changes, or the song could be major or minor?
The key finder reports one key for the whole file, so a song that modulates gets the key that fits most of it. A relative major and minor share notes and are easy to mix up, so check that pair by ear.
What are the related keys, and are they Camelot codes?
The key finder shows key names, not Camelot codes. A major key lists its relative minor and the majors a fifth and a fourth up; a minor key lists its relative major and the minors a fifth and a fourth up. A Camelot wheel places the same three beside yours.
Can the key finder listen through a microphone or read a vocal?
No. It reads a file you choose and cannot listen through a microphone. A vocal recording works as a file, but a short clip has few notes to measure, so confirm by ear.
Which files work, and is my song uploaded?
MP3, WAV, FLAC, OGG, AAC, M4A and WebM work, up to 80 MB and 5 minutes on desktop or 2 on mobile. It is free with no account, and the file stays in your browser. The sample is Bach's Prelude No. 1 in C major by Kimiko Ishizaka, under CC0.
