Why do I need to know a song's key?

The key tells you which notes and chords fit the song, so you can find backing tracks, transpose it to suit your voice or instrument, harmonize, or warm up in the right place before you sing. On PitchHighway, knowing the key is the first step to learning to sing the whole song.

Song Key Finder — Find a Song's Key Free

Find the Key of Any Song, Free

Find the key of a song in seconds with this free song key finder. See the detected major or minor key, its relative key and a confidence level. Choose an MP3, WAV or other supported audio file to analyze in your browser. Your music never leaves your device, and there's nothing to install or sign up for.

How the Key Finder Works

Add Your Song

Drop an audio file (MP3, WAV, M4A, FLAC, or OGG) onto the page, or tap to choose one from your device.

Analyze

The tool decodes the audio in your browser and builds a chromagram — a measure of how much of each of the twelve notes the song uses.

Read Your Key

See the detected key and its relative major or minor, a confidence level, and the other most likely keys.

What Is a Song's Key?

A key is the group of notes a song is built from and the note it feels resolved on — its musical "home base." Knowing the key tells you which notes and chords belong, so you can transpose the song, find backing tracks, harmonize, or warm up in the right place before you sing.

Major vs. Minor

Major keys tend to sound bright and resolved; minor keys sound darker or more tense. The tool detects which mode fits the song and names it, e.g. "G major" or "E minor."

The Relative Key

Every major key shares its exact notes with one minor key (C major and A minor, for example). Because they use the same notes, the tool shows the relative key too — whichever the song resolves to is the true one.

What You Can Do With the Key

Sing It in Your Range

Once you know the key, you can transpose a song up or down so it sits comfortably in your voice instead of straining for notes.

Play Along

Find chords, backing tracks, and karaoke versions in the right key, or work out the song on guitar or piano faster.

Harmonize

Knowing the key and its scale makes it far easier to add harmonies that fit and to improvise over the track.

Warm Up Right

Warm up your voice around the song's key so you're ready to sing it — then upload it to PitchHighway to learn the whole thing.

Frequently Asked Questions

How do I find what key a song is in?

Drop an audio file of the song onto this page. The tool decodes the audio in your browser, measures how much energy sits on each of the twelve musical notes, and matches that fingerprint against all 24 major and minor keys to name the most likely one — in a few seconds, with no upload and no signup.

Is the song key finder accurate?

For most songs with a clear tonal center it names the correct key or its relative major/minor, which share the same notes. Accuracy drops for tracks that change key, are heavily percussive, or are very quiet — the tool shows a confidence level so you know when to treat the result as a best guess.

Do you upload my music file?

No. The whole analysis runs in your browser using the Web Audio API. Your file never leaves your device and is never sent to a server, so it even works offline once the page has loaded.

What is the relative key it shows?

Every major key shares its notes with one minor key a minor third below it — for example C major and A minor. Because they use the same notes, a key finder can't always tell them apart from audio alone, so the tool shows the relative key too. Whichever note the song resolves to is usually the true key.

Which audio formats work?

Any format your browser can decode — commonly MP3, WAV, M4A/AAC, FLAC, and OGG. If a file won't decode, try exporting it as MP3 or WAV.

Find Your Song's Key