How to change audio speed or pitch
- Drop an audio file on the box. It is read in a few seconds.
- Set the speed (0.25× to 4×) and the pitch in semitones (-12 to +12). The new length is shown below.
- Press "Preview first 30 s" to listen to the result quickly.
- Choose a format and press "Change and save" to process the whole file.
To practice a song, try 0.75× speed with the pitch left at 0. To match a song to your voice, change only the pitch.
Questions
Is my audio uploaded?
No. The sound is changed by code running in this browser tab. Nothing is sent anywhere.
How can the speed change without the pitch changing?
The sound is cut into tiny overlapping pieces. For a faster result, some pieces are skipped; for a slower one, some are repeated. Each piece is placed where it matches its neighbor best, so voices and instruments keep their natural pitch. This method is called WSOLA.
How do I change pitch without changing speed?
Move the pitch slider. Every 12 semitones is one octave. The length stays the same. Use small steps (1 to 3 semitones) for the most natural result; large shifts make voices sound unnatural.
What does "Change pitch together with speed" do?
It plays the audio faster or slower like a tape or a record, so a faster song is also higher. It is useful for a nightcore effect or to slow a song down for practice with the original sound character.
Which speeds work best?
Between 0.5× and 2× sounds good. Beyond that you may hear a little warbling because so much of the sound is repeated or skipped. Use the 30 second preview to check before saving the whole file.
Credits
Built on Mediabunny (MPL-2.0), LAME MP3 encoder (via @mediabunny/mp3-encoder) (LGPL-2.0) and FFmpeg AAC encoder (via @mediabunny/aac-encoder) (LGPL-2.1-or-later). OneTooling is not affiliated with these projects.