The method this tool uses is resampling through the Web Audio API's playback rate control, and it comes with an important trade off you should understand before relying on it: resampling changes pitch and tempo together, in lockstep, exactly the way speeding up or slowing down a tape or vinyl record does. Raising the pitch necessarily shortens the file's duration, and lowering the pitch necessarily lengthens it. There is no way around that with this technique, because pitch and playback speed are the same variable at the sample rate level.
Everything runs locally on your device. Decoding, the resampling itself and the final WAV encoding all happen in your browser tab using the Web Audio API, so a private recording never has to be uploaded anywhere just to have its pitch adjusted.
This audio pitch changer shifts pitch without pretending tempo stays put
Every sample in a decoded audio buffer represents air pressure at one instant in time, spaced apart by the sample rate. Reading those samples faster than they were recorded raises pitch because the same waveform now completes more cycles per second, and reading them slower lowers pitch for the opposite reason. That relationship is fixed and physical, not a setting this tool chooses, and it is exactly why an audio pitch changer built this way must also change duration whenever it changes pitch.
This is genuinely different from the pitch shifting used in professional music software, which relies on a phase vocoder or a similar algorithm to separate pitch from time so a vocal can be shifted up a third while the song keeps its original tempo. Building that kind of algorithm well is a substantial piece of signal processing work, and this tool intentionally does not attempt it, since a resampling based shifter that is honest about its trade off is more useful than one that quietly produces warped or unreliable results trying to fake time independent pitch shifting.
- Use this audio pitch changer when a small pitch adjustment with a matching tempo change is acceptable.
- Expect the output to run shorter when you raise pitch and longer when you lower it.
- Reach for dedicated time stretching or phase vocoder software when you need pitch changed without tempo changing.
- Keep changes moderate, within a few semitones, for the most natural sounding result.
Why raising or lowering pitch also changes tempo and duration
Semitones on the slider are converted into a playback rate multiplier using the same formula a piano tuner or a musician would recognise: each semitone corresponds to a factor of the twelfth root of two, so shifting up by twelve semitones, a full octave, doubles the playback rate, while shifting down by twelve semitones halves it. A rate of 2 plays every sample in half the original time, so a three minute song shifted up an octave finishes in one minute and thirty seconds, unmistakably faster as well as higher.
This is worth stating plainly rather than hiding behind a slider that only mentions pitch. If you need a backing track to match a singer's range without dragging or rushing the tempo, this resampling approach will not deliver that, since duration always moves with pitch here. It is the right tool when a joint shift in both is fine, such as quick creative experiments, sound design or matching a sample to a different key when timing is flexible.
Choosing a pitch shift amount
Small shifts, within two or three semitones in either direction, sound closest to the original character, since the underlying waveform is only being stretched or compressed slightly and most listeners will not immediately notice the tempo has moved too. This is the range that suits matching a recording to a slightly different key.
Larger shifts, particularly beyond an octave in either direction, produce the more dramatic and recognisable effects, the classic helium voice from a large upward shift or the ominous slow motion character from a large downward one, alongside an equally dramatic change in duration that becomes hard to ignore at that scale.
Resampling the buffer at a different rate is the whole trick
The decoded AudioBuffer is rendered through an OfflineAudioContext with its buffer source node's playbackRate property set to the rate calculated from your chosen semitone value. That single property change resamples the entire signal in one pass, producing both the shifted pitch and the correspondingly shorter or longer duration as one unavoidable, connected result of the same operation.
The rendered buffer is then encoded as a standard 16 bit PCM WAV file using a hand written encoder, since browsers can decode compressed formats but cannot reliably re encode them without a licensed codec. The playback rate change and the render both happen against the AudioBuffer already sitting in the tab's memory, so there is no intermediate step where the file would pass through anything but your own device.
How to change the pitch of audio
- 1
Add your audio file
Drag an audio file onto the drop area, or click it to browse. MP3, OGG, FLAC, M4A, AAC and WAV are all accepted.
- 2
Set the pitch shift in semitones
Move the slider up to raise pitch or down to lower it. The resulting duration change is shown alongside it.
- 3
Process the file
Press process and wait for the resampling to render. Larger shifts take slightly longer since the output is a different length.
- 4
Download the shifted WAV
Download the result. Remember its duration differs from the original by the same ratio as the pitch shift.
Related tools worth bookmarking
Sources and further reading
Frequently asked questions
Common questions about the audio pitch changer.
No, and this is the single most important thing to know before using it. The tool shifts pitch by resampling, which ties pitch and playback speed together the same way a tape or record does, so tempo and duration always change along with pitch. There is no setting here that isolates one from the other.
Duration scales inversely with the playback rate the shift produces. Raising pitch by a full octave, twelve semitones, doubles the rate and halves the duration, while lowering by an octave halves the rate and doubles the duration. Smaller shifts of a few semitones change duration by a correspondingly smaller amount.
Not with this tool. True independent pitch and tempo control requires a phase vocoder or similar time stretching algorithm, which is a different and more complex piece of signal processing than the resampling approach used here. This audio pitch changer is honest about that limit rather than attempting a poor approximation.
Keep the shift small, within two or three semitones, since that limits both the tonal change and the accompanying tempo shift to something most listeners will not immediately notice. Large shifts of an octave or more produce dramatic, obviously altered results in both pitch and speed.
It can shift a recording into a nearby key, but because tempo moves with pitch, the result will also play faster or slower than the original. For matching a backing track to a different key while keeping the same tempo, dedicated key changing software that separates pitch from time is the more appropriate tool.
Resampling itself is mathematically clean, so it does not add distortion the way a phase vocoder's overlap and blend seams can. What you will notice at large shifts is the physical result of the technique: formants and timbre shift along with pitch, which is why an octave up sounds like a chipmunk rather than a taller version of the same voice.
Yes. This page lets you change pitch of audio directly in a browser tab, with no installation and no account, by dragging in a file, choosing a semitone shift and downloading the resampled WAV a few seconds later.
Yes. This tool lets you pitch shift audio online at no cost and adds nothing to the output file. The resulting WAV contains only the resampled audio, with no watermark, tone or branding inserted anywhere in the recording.