Audio Pitch Changer

How to change the pitch of audio

Three steps, in your browser.

1. 1

   Drop the file

   A song, a backing track or a voice recording: MP3, M4A, WAV, FLAC and other common formats up to 100 MB and 30 minutes.

2. 2

   Pick the shift and listen

   Move the slider from -12 to +12 semitones, fine-tune in cents if you need to, and pick the song's key to see where it lands. Make a preview of the first 30 seconds and switch between the original and the new pitch while it plays.

3. 3

   Process and download

   The whole file is shifted with a progress bar and saved as an MP3 at the bitrate you choose or as a 16-bit WAV. The length is exactly the same as before.

Pitch without speed

• Semitones and cents

  A semitone is one key on a piano. Twelve of them make an octave, which doubles or halves every frequency. Cents divide a semitone into 100 steps, for the small corrections a key change cannot make.

• A pitch shifter online, not a speed trick

  Playing a recording faster also makes it higher, like a tape at the wrong speed; the Audio Speed Changer's Let the pitch change mode does exactly that. This page moves the pitch and leaves the tempo alone, so a 3:30 song is still 3:30.

• How it works

  The file is first stretched longer or shorter without touching its pitch, by cutting it into short overlapping slices of about 40 milliseconds and laying them out again, then played back faster or slower to bring it to its original length. The two steps together leave the length as it was and move every frequency.

• What it costs in quality

  One to three semitones on a voice or a solo instrument usually sound natural. Large shifts on a full band mix can sound smeared or a little hollow, and a voice moved far up or down takes on a cartoon or giant quality, because its resonances move with it. That is a limit of the method, not of this page.

When a pitch change helps

• Transpose a backing track to your voice

  If the chorus sits too high, take the track down two or three semitones and try again. Pick the song's key in the tool and it tells you the new one, so you can tell the band or the pianist.

• Practise an instrument in another key

  Shift a recording to the key your instrument is tuned to, or down a semitone to match a guitar tuned to E flat, and play along at the original tempo.

• A deeper or brighter voice for a video

  A semitone or two down gives a narration more weight; one or two up makes it sound lighter. It is not a safe way to hide who is speaking: shifting the file back undoes it.

• Fix a recording that plays sharp or flat

  An old tape transfer or a phone recording can come out a little off. Move the cents slider until it matches a tuner or the instrument you are playing with.

Semitones, intervals and frequency

Each semitone multiplies every frequency by the twelfth root of 2, about 1.059.

What a pitch change does not change