How does pitch shifting work without changing speed?

The tool uses the asetrate + atempo trick in ffmpeg: it changes the sample rate to shift pitch, then corrects the speed with atempo, and resamples back to 44100 Hz. This gives clean pitch shifting without any tempo change.

A semitone is the smallest interval in Western music — the distance between two adjacent keys on a piano. 12 semitones = 1 octave. Shifting +5 semitones raises the pitch by a perfect fourth; +7 raises it by a perfect fifth.

Can I use this for harmonic mixing?

Yes. If two tracks are in compatible keys but not the same key, you can shift one track by the right number of semitones to match. Use our Key Detector to find the keys first, then calculate the semitone difference.

Will the duration change when I shift pitch?

No. The atempo correction ensures the duration stays exactly the same. Only the pitch changes.

Yes, 100% free. No account, no upload, no limits. Processing happens entirely in your browser using ffmpeg.wasm.

Pitch Changer Online

Shift the pitch of any audio file by semitones without changing speed. Perfect for remixing, key matching, and music practice. No upload required.

−12 to +12 SemitonesSpeed PreservedNo Upload100% Free

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Pitch Shift

0semitones

Original

-12 (−1 octave)0 (original)+12 (+1 octave)

What Is Pitch Shifting and When Do You Need It?

Pitch shifting changes the musical key of an audio file without affecting its duration or tempo. Shifting +1 semitone raises the pitch by one half-step; shifting −12 semitones lowers it by a full octave.

Our pitch changer online supports −12 to +12 semitones — a full two-octave range. The speed stays exactly the same thanks to automatic tempo correction.

Common Use Cases

Match the key of two tracks for harmonic mixing without re-recording
Transpose a sample to fit the key of your production
Practice singing or playing in a different key
Create harmonies by layering the original with a shifted version
Fix slightly off-key recordings without re-recording

How the Pitch Shifting Algorithm Works

The tool uses the asetrate + atempo technique in ffmpeg — a reliable method for pitch shifting without duration change:

Step 1: asetrateChanges the sample rate by the pitch ratio (2^(semitones/12)). This shifts pitch but also changes speed.

Step 2: atempoCorrects the speed back to the original duration using the inverse ratio.

Step 3: aresampleResamples the audio back to 44,100 Hz for standard playback compatibility.

Example: +5 semitones (perfect fourth up)

asetrate=58,680 (44100 × 2^(5/12))

atempo=0.7491 (speed correction)

aresample=44100

Semitone Reference: Common Intervals

Here are the most musically useful pitch shifts and what they mean:

+12 stOne octave upSame note, higher register

+7 stPerfect fifth upBright, harmonically compatible

+5 stPerfect fourth upWarm, harmonically compatible

+2 stMajor second upSubtle key change

0 stUnisonNo change

−5 stPerfect fourth downDarker tone

−7 stPerfect fifth downDeep, harmonically compatible

−12 stOne octave downSame note, lower register

Frequently Asked Questions

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From the Blog

Music TheoryPitch Shifting Explained: How It Works and When to Use ItDeep dive into pitch shifting algorithms, semitone intervals, and how to use pitch shifting for harmonic mixing.

Music TheoryHarmonic Mixing: The Key to Professional DJ SetsUse the Camelot wheel to find compatible keys and create smooth, musical transitions.