Change the pitch or speed of audio
Change the key of a song, or play it faster or slower, keeping the other the same. Done on this device.
- Nothing is uploaded
- Works offline after first use
- Open source
- No watermark · limit is your device’s memory; phones hold less
Shifts a song or recording up or down by semitones without changing its length, or changes its speed without changing its pitch (MP3, WAV, M4A, FLAC). It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory, and phones hold less; give the page a short while after your first run to save itself for offline use, and then it works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
How it works
- Drop one or more sound files (MP3, WAV, M4A, FLAC, OGG), or tap to pick them.
- Move the pitch in semitones, choose a speed, or both. Keep the original format or pick another.
- Run it. Each file downloads when it is ready; several come as a zip.
In your browser, not on a server
Your browser’s own audio decoders read the file in the tab. The speed is changed with WSOLA (waveform-similarity overlap-add): the sound is cut into overlapping 43 ms windows, spread out or packed together, and each window is nudged to line up with the one before so there are no clicks. The pitch is then moved by resampling through a windowed-sinc filter, which also shortens or lengthens the sound, so the stretch is sized to leave exactly the speed you asked for. The result is written with the same encoders as the audio converter.
Compared with upload-based tools: Online pitch shifters upload the whole song or recording and many cap the length or the number of files on a free plan. Here the file never leaves your device, a whole album can go in one batch, and nothing is added to the sound.
Verify it yourself. Give the page a short while after your first run to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Is my audio uploaded?
No. Your browser decodes the sound, the pitch and speed change run in the page, and the file is written again in your tab. Your files are not uploaded, and it works offline after your first run.
How do I change the key of a song?
Move the pitch slider by the number of semitones between the keys: from C to D is +2, from E to C is −4. The tempo and length stay the same, so you can sing or play along in a key that suits your voice or instrument.
Will speeding up make voices sound like chipmunks?
No. Speed changes keep the pitch unless you tick the option to let the pitch follow the speed, which gives the record-player effect some people want for sped-up or slowed songs.
How good is the quality?
Small changes, a few semitones or up to about 1.5× speed, sound natural. Very large ones, a whole octave or half speed, add some smearing, as every pitch shifter does. Save as WAV or FLAC if you will edit the result further.
Can I use it on a video?
This page takes sound files. For a video, use Change video speed, which keeps the pitch of the voices, or save the sound first with Video to MP3.
More video and audio tools
BPM and key finder
Drop an audio file and read its tempo, key and Camelot code. The song is analysed on this device.
Online tuner
Play a note and see how sharp or flat it is. Guitar, bass, ukulele, violin or chromatic, with the sound kept in your tab.
Metronome
A steady click at any tempo, with the bar, the subdivisions and tap tempo, running on your device.
Blur faces in video
Faces found and covered frame by frame, on your own device, for children, bystanders and anyone who did not agree to be filmed. Always watch the result before you share it.