Pitch Changer

About Pitch Changer

This free tool changes the key of a song and keeps the tempo the same. Move it up to 12 semitones higher or lower — a whole octave — and fine tune it in cents. The song does not get faster or slower; only the notes move.

When you pick a number of semitones, the page shows the new key. The tool makes a best guess of the song's key for you, and you can pick the right key yourself if you know it.

Everything happens in your browser. Your song is never uploaded.

Features

• ±12 semitones — from an octave down to an octave up, one piano key at a time
• Fine tune ±50 cents — to match a piano or a band that is a little out of tune
• The tempo stays the same — the song keeps its length and its beat
• New key shown — the tool guesses the song's key, and you can set it yourself
• Made for music — a phase vocoder with phase locking, and both stereo channels moved together
• Long songs — a 10-minute song is done in seconds, with a progress bar, and the page does not freeze
• MP3 or WAV — MP3 from 128 to 320 kbps, or lossless WAV, with one-click download
• Private — no upload, no sign-up, no watermark

Semitones, cents and keys

• A semitone is the step from one piano key to the next (white or black). +2 moves C major to D major. −3 moves A minor to F♯ minor.
• 12 semitones is an octave: the same notes, one octave higher or lower.
• A cent is a hundredth of a semitone. Use it to match a recording that is a little sharp or flat, for example a song tuned to 432 Hz is about −32 cents from the usual 440 Hz.

Finding the key. The tool listens to the whole song, counts how much of each note it hears, and picks the key that fits best. For most pop songs the guess is right, but it can mix up a major key and its minor key (C major and A minor share the same notes). If you know the key, pick it in the list.

How it works

To move the key and keep the tempo, the tool does two things in your browser:

1. It stretches the song in time without changing the pitch, with a phase vocoder — it cuts the sound into short, overlapping slices, works out the notes in each slice, and lays them out again at a new spacing.
2. It resamples the song back to its own length, which moves every note up or down by the amount you chose.

The two steps cancel out in time, so the length and the beat stay the same, and only the key moves. Small changes (a few semitones) sound the most natural. Big changes, like a whole octave, always sound a little less natural, because voices and instruments change their colour, not just their pitch.

This is not a voice effects tool. For chipmunk, robot or deep-voice effects on your own voice, use the Voice Changer. To change the speed instead of the key, use the Audio Speed Changer. For the slowed sound, where the pitch goes down with the speed, use Slowed + Reverb.

Common uses

• Singing and karaoke — move a song to a key that fits your voice
• Playing along — match a recording to your guitar, piano or band
• Practice — play a song in another key to learn it there
• Tuning — fix a recording that is a little sharp or flat with cents
• Remixes and edits — raise or lower a track to mix it with another one

Frequently asked questions

Is it free, and is my song uploaded?

It is free, with no sign-up and no watermark. The key is changed in your browser and the song is never sent to a server.

Does the speed change?

No. The tempo and the length stay the same. Only the key moves.

How many semitones should I move to fit my voice?

Try 1 or 2 semitones at a time, up or down, and sing along. Most people find a good key within 3 semitones of the original. Women singing a song by a man (or the other way) often move it about 5 semitones.

Why does a big change sound strange?

At 8 to 12 semitones, a voice starts to sound like a different person, because the tool moves the whole sound, including the colour of the voice. That is normal for every pitch changer. Smaller changes sound the most natural.

Is the key guess always right?

No. It is a best guess from the notes in the song. It is often right for pop songs, but it can pick the related major or minor key. Pick the right key in the list if you know it; the new key is shown from your choice.

Is what I hear the same as the file I download?

Yes. You hear the finished result. When you change the key, the new version is made in the background (a progress bar shows it); until it is ready you hear the last one, and the Download button comes back when the file is ready.

How to use it

• Drop a song on the box, or click it to choose one
• Move the Key change slider — each step is one semitone — and see the new key
• Use Fine tune for small changes in cents
• Press Play to listen; the tempo stays the same
• Choose MP3 or WAV, then press Download