Voice Changer - Pitch Shift Your Voice in the Browser

How to use this tool

Click "Start Recording" and allow microphone access.
Speak, then click "Stop Recording".
Choose a pitch preset or set a custom rate.
Click "Play Shifted" to hear the take at the chosen playback rate; this also changes its duration.
Click "Download original recording" to save the unshifted take. Pitch shifting applies during playback only; the downloaded recording remains unshifted.

How the voice changer works

Your microphone input is captured using the MediaRecorder API and stored locally as an audio blob. When you play back the recording, the HTML5 audio element's playbackRate property shifts the pitch - faster playback raises pitch, slower playback lowers it. This technique is time-domain pitch shifting: it changes frequency and duration simultaneously (unlike professional phase-vocoder algorithms that decouple the two).

Audio effects glossary

This is a reference glossary, not a list of controls. This tool offers pitch up and down by changing playback rate. Reverb, echo or delay, distortion, low-pass filtering, and bit-crush are described for context but are unavailable here.

Effect	Availability	How it works	Typical use
Pitch up (chipmunk)	Available — playback-rate control	playbackRate > 1.0 — faster replay raises pitch	Cartoon voices, comedy
Pitch down (deep)	Available — playback-rate control	playbackRate < 1.0 — slower replay lowers pitch	Monster voices, radio DJ effect
Reverb	Unavailable here — reference only	Convolution with an impulse response (simulates room reflections)	Concert hall, cathedral
Echo / delay	Unavailable here — reference only	Copies of the signal played back after a set delay time	Slap-back, dub, stadium
Distortion / overdrive	Unavailable here — reference only	Clips or soft-saturates the waveform, adding harmonics	Guitar amp, robot voice
Low-pass filter	Unavailable here — reference only	Removes high frequencies above a cutoff Hz	Telephone or walkie-talkie effect
Bit crush	Unavailable here — reference only	Reduces bit depth, creating quantisation noise	Retro / 8-bit sound

Privacy

Your voice recording never leaves your device - no server or network request is made.

Phase vocoder vs. playback-rate pitch shifting

The pitch effects in this tool are implemented by changing the audio playback rate - playing audio faster raises pitch but also shortens duration. Professional-grade pitch changers use a phase vocoder, which shifts pitch independently of playback speed by splitting audio into frequency bands, shifting each band, and reassembling. Phase vocoders can raise or lower pitch without changing duration at all. Implementing a phase vocoder in the browser requires an AudioWorklet and significant DSP code; the playback-rate approach is far simpler and good enough for fun effects.

Reverb types

Reverb is not available in this tool; the notes below explain how audio software can simulate reflections from walls and surfaces in a physical space. Two main approaches:

Algorithmic reverb: uses feedback delay networks to approximate a space. Fast and controllable but can sound artificial.
Convolution reverb: convolves the dry signal with an impulse response (IR) - a recording of how a real space responds to a brief impulse. Sounds extremely realistic. The Open AIR library provides free IRs of real spaces ranging from small rooms (~100 ms decay) to cathedrals (2–5 second decay).

Use case examples

Podcast voice practice: try the Low preset or a rate just below 1× to hear a lower, slower take. Playback-rate shifting also changes duration; this tool does not add reverb.
Character voice ideas: record a line and audition a higher or lower playback for a game character. The tool plays back a finished take; it does not alter live voice chat.
Accessibility: pitch shifting can help users with voice conditions communicate more comfortably.
Teaching demonstrations: exaggerated pitch effects make audio concepts engaging for students.

Frequently asked questions

How does the pitch change work?

Your voice is recorded with MediaRecorder and played back via an HTML5 audio element at a different playback rate. Doubling the rate raises the pitch by one octave; halving it lowers by one octave.

Is my voice sent to a server?

No. Recording and playback happen entirely in your browser using local memory.

Why does the duration also change?

This tool uses simple rate-based pitch shift which also changes duration. For time-preserving pitch shift a DSP algorithm (phase vocoder) would be needed.