Pitch Shifter

Shift the pitch of an audio file without changing its speed.

Everything runs in your browser. No audio is ever uploaded.

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Pitch shift0

Move the slider in semitones. Negative values lower the pitch, positive values raise it, and the duration stays the same.

This pitch shifter transposes an audio file up or down by as much as twelve semitones, a full octave in either direction, while the file stays exactly as long as it was. Everything happens in your browser: the file is decoded, processed and written back out as a WAV without ever being uploaded. You can switch between the original and the result at the same playback position before you decide to keep it.

How to use it

Choose an audio file or drag it onto the box. Files over 30 MB get a warning because everything is held in the tab's memory, and files over 150 MB are refused outright.
Move the pitch slider. The scale runs from -12 to +12 semitones in whole steps, so +2 is a whole tone up, +7 is a fifth, and +12 or -12 is a full octave. Zero leaves the file untouched.
Press Apply and wait. A progress bar shows how far the processing has got, and Apply turns into Cancel while it runs, because the work happens in the page rather than on a server and a long file takes real time.
Compare before you commit. The Original and Result buttons swap the player between the two files at the same position, which is the only honest way to judge whether a shift did what you wanted or just made the recording sound processed.
Download the result as a WAV file. If your input was compressed, the download is larger than the file you started with, because WAV stores every sample uncompressed.

What you can use it for

Moving a backing track into your key. If a song sits two semitones too high for a singer, shift it down by two and the tempo, the arrangement and the length all stay exactly as they were.

Practising a part written for another instrument. A guitar player can drop a track by a couple of semitones instead of reaching for a capo, and a horn player can move a piece between concert and transposed pitch.

Fitting a sample into a track. A loop borrowed from another song rarely lands in your key, and a shift of a few semitones is usually the smallest change that makes it usable.

Changing how a voice sounds in a video. A shift of a few semitones is enough to disguise a voice or make a character sound different. Large shifts sound processed rather than natural, which may or may not be what you wanted.

Hearing a part in another register before you rerecord it. Moving a bass line up an octave or a lead down one tells you quickly whether the idea is worth playing again properly.

Semitones and the intervals they give you

Shift	Interval	What it does
+1	Minor second	One fret, one piano key, one half step. The smallest move in standard western tuning and often all a singer needs.
+2	Major second, a whole tone	The everyday transposition, and the same thing as a capo on the second fret. Small enough that artifacts stay out of the way.
+5	Perfect fourth	The distance between most adjacent guitar strings, and a common jump between vocal keys.
+7	Perfect fifth	A large move that changes the character of the recording noticeably, not only its key.
+12	Octave up	Doubles every frequency. Voices start to sound thin and cartoonish, because the resonances of the body move up with the pitch.
-12	Octave down	Halves every frequency. The most demanding setting here, and the one where smearing on transients is easiest to hear.

Accuracy and limits

This is a phase vocoder, and phase vocoders leave a signature. The audio is broken into overlapping frames of about 2048 samples, rebuilt at a new pitch and added back together, which means sharp transients such as drum hits, guitar plucks and hard consonants get smeared across a few milliseconds, and sustained sound can pick up a faint metallic or watery edge. A shift of one or two semitones is usually clean enough that nobody notices; a full octave on percussive material is obvious.

Formants move with the pitch, because nothing here separates them out. A voice shifted up sounds like a smaller person, not like the same person singing higher, and a voice shifted down gains a hollow quality. There is no formant correction, so plan for the character change rather than being surprised by it.

Processing runs in the page, on the main thread, so a long file takes a while and the tab needs to stay in the foreground. The size guards exist for the same reason: decoding a file, holding the result and writing a WAV all consume memory at once. The output is always WAV, so compressed input comes back larger.

Frequently asked questions

Does changing the pitch change the tempo?

No. That is the entire point of the tool. Speeding a recording up would raise its pitch as a side effect, but this stretches the audio in time first and then resamples it, so the result comes out at the new pitch and the original length.

How far can I shift?

Twelve semitones up or down, which is one octave in either direction. The limit is deliberate: past an octave the phase vocoder artifacts stop being a subtle texture and become the main thing you hear.

Why does the result sound metallic or smeared?

Because of how phase vocoding works. Rebuilding audio from overlapping frames blurs sharp attacks and can add a slight ringing to steady tones. Use the smallest shift that does the job, and expect percussive material to suffer more than sustained material such as pads or strings.

Can I change the key of a song with this?

Yes. Count the semitones between the two keys and set the slider to that number: C to D is +2, C to F is +5, C to G is +7. The table above lists the common intervals.

What format do I get back?

An uncompressed WAV file, which is why the download is bigger than an MP3 input. WAV avoids adding another lossy encoding step; if you need an MP3, convert the WAV afterwards with any converter or editor.

Is my file uploaded?

No. The file is decoded and processed in your browser, and the result exists only as a temporary link in the page until you download it. Nothing is sent anywhere, and closing the tab discards it.