NEW · FFmpeg.wasm · 100% Browser-Based

Audio Pitch Shifter

Shift the pitch of any audio file by up to ±12 semitones without changing its duration — useful for voice correction, music transposition, and anonymizing voiceover. FFmpeg.wasm runs locally. No upload, no signup, no watermark.

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Drop an audio file
MP3 · WAV · AAC · OGG · FLAC · M4A
Files stay on your device · Never uploaded

Related Tools on UDT

Audio Tempo Changer →
Change playback speed without affecting pitch — the inverse operation.
Audio Normalizer →
EBU R128 loudness normalization to broadcast standards.
Audio Converter →
Convert between MP3, WAV, AAC, OGG, FLAC, and M4A.
All Audio Tools →
Browse the full Audio Suite — 13 tools, all in-browser.

Why Do This in Your Browser?

Pitch shifting without changing duration used to mean opening a DAW, hunting through plugin menus, finding a time-domain shifter, dialing it in by ear, and bouncing the result. For a single instrument practice take or a podcast voice tweak, the friction is the whole job. The math behind pitch-preserved time stretching is non-trivial — it requires resampling combined with phase-aware time correction — but it has been a solved problem since the 1990s and FFmpeg ships the algorithm built in.

Run the shift in your browser. The audio never leaves your device. The 32MB FFmpeg.wasm engine is the same one used by the Audio Trimmer, Normalizer, and the Video Suite — load it once and every later operation across the suite starts instantly.

How It Works

Drop an audio file. Set the pitch shift in semitones using the slider (range ±12 — a full octave each direction). Positive values raise the pitch; negative values lower it. Duration stays exactly the same — only the pitch changes. Preview the slider position before committing to the export.

Under the hood, the tool applies FFmpeg's standard pitch-shift chain: `asetrate` to scale the sample rate by `2^(semitones/12)`, `aresample` to bring the rate back to a standard frequency, then `atempo` with the inverse factor to restore the original duration. The result is a pitch shift with the same playback length — voice gets higher or lower, music transposes up or down a key, all while the song's tempo stays put.

Tip: For changing playback speed without affecting pitch, use the Audio Tempo Changer instead — it does the opposite operation. To run a final loudness pass after pitch correction, the Audio Normalizer brings the result to distribution-ready levels.

Common Use Cases

Voice Pitch Correction
Raise a voice take by 1–2 semitones to brighten without re-recording. Useful for podcast intros where the natural delivery was a little flat.
Music Transposition
Shift a song up or down a few semitones to match a vocalist's range or a specific instrument tuning. Common need for cover song practice tracks.
Voice Anonymization
Shift a voiceover down 4–6 semitones to disguise the speaker. Combined with a slight tempo change, the result resists basic voice recognition.
Sample Repitching
Transpose a one-shot sample to a different musical key without re-rendering it from the source instrument.
Cartoon Voice Effects
Shift up 6–12 semitones for chipmunk-style effects. Shift down for monster voices.
Karaoke Key Matching
If a karaoke backing track is in the wrong key for your voice, shift it 1–3 semitones up or down to make it singable.

How We Compare

Honest read on free, paid, and self-hosted options for this kind of job:

UDT Audio Pitch Shifter (this tool): Free, browser-based, FFmpeg.wasm asetrate/atempo chain. ±12 semitones, duration preserved, instant preview. No upload, no watermark, no signup.
Audacity (desktop): Free, full audio editor. The Effect > Pitch (Shift) menu does the same job with more options (formant preservation). This browser tool is the focused alternative — no install, no project to manage.
Adobe Audition: Creative Cloud $20+/mo. Pitch-shift effect with formant preservation. Higher quality than free tools for vocal work.
Online MP3 pitch shifters (cloud): Several free options. Most require upload, free tier caps file size, output is usually 128kbps MP3. UDT runs entirely in your browser.
FFmpeg CLI: Free, command-line; same engine as this tool. asetrate=44100*2^(N/12),aresample=44100,atempo=2^(-N/12). This is FFmpeg with a UI.
Logic Pro / Ableton Live: Pro DAWs ($199–$749) with high-quality time-domain pitch shift. For tracking sessions, you'd use these. For a single file tweak, this browser tool is the faster path.

Frequently Asked Questions

Is this audio pitch shifter really free?+
Yes — completely free, no watermark, no time limits, no signup. The site is supported by ads elsewhere; the tool is unrestricted.
Does the duration change when I shift the pitch?+
No. That is the whole point of a pitch shifter as opposed to a simple speed change. The tool uses an asetrate + aresample + atempo chain so the output file length matches the input exactly. Only the pitch changes.
How many semitones can I shift?+
Up to ±12 semitones — a full octave in either direction. Beyond that, audio quality degrades enough that the result rarely sounds usable. For larger shifts, consider re-recording or using a dedicated DAW with formant-preserving algorithms.
What does a 'semitone' mean musically?+
A semitone is the smallest interval in Western music — the gap between two adjacent piano keys (white and black included). Twelve semitones make up an octave. Shifting +1 semitone takes C to C-sharp; +12 takes C up to the next C.
Are my audio files uploaded anywhere?+
No. FFmpeg.wasm runs entirely in your browser. The 32MB engine downloads once and caches; after that, the tool works fully offline.
Why does shifted audio sometimes sound slightly metallic?+
Pitch-preserved shifting uses time-stretching algorithms that can introduce minor artifacts at extreme shifts. Shifts within ±3 semitones usually sound transparent; shifts beyond ±6 start to color the audio. For broadcast-quality work, a DAW with formant preservation will sound cleaner.
What's the maximum file size?+
Limited by browser memory. Most laptops handle 1–2GB audio files comfortably; phones cap around 500MB.
What's the underlying engine and license?+
FFmpeg.wasm v0.12.x with @ffmpeg/core v0.12.6 (asetrate, aresample, atempo filters built in). FFmpeg itself is LGPL-licensed; the wasm wrapper is MIT.