UtilityKit

500+ fast, free tools. Most run in your browser only; Image & PDF tools upload files to the backend when you run them.

Audio Speed & Pitch Changer

Speed audio up or slow it down without changing pitch, or shift pitch in semitones independently of speed. MP3, WAV, M4A, OGG, FLAC. ffmpeg.wasm in browser.

About Audio Speed & Pitch Changer

Audio Speed & Pitch Changer adjusts the tempo and/or pitch of an audio file independently. Drop in MP3, WAV, M4A, OGG or FLAC, set a speed multiplier (0.25× to 4×) and a pitch shift in semitones (-12 to +12), and the tool re-encodes the audio so they apply separately. By default, speed changes preserve pitch (atempo filter) and pitch shifts preserve speed (asetrate + aresample, then atempo to compensate). A 'link speed and pitch' checkbox enables vinyl-style behaviour where speeding up also raises pitch — same as cranking a turntable. Use it to slow a guitar solo for transcription, transpose a karaoke backing track, speed up a podcast without chipmunk effects, or experiment creatively with pitch and tempo. Everything runs locally via ffmpeg.wasm — files never leave your device.

Why use Audio Speed & Pitch Changer

  • Independent speed and pitch — change one without affecting the other
  • Vinyl-style linked mode for classic turntable-feel pitch up/down
  • Wide range: 0.25× to 4× speed, ±12 semitones pitch
  • atempo chaining handles any speed multiplier (not just 0.5–2×)
  • 100% browser-side — files never leave your device
  • Free, no watermark, no signup, no daily cap

How to use Audio Speed & Pitch Changer

  1. Click or drag your audio file onto the upload area.
  2. Set the speed slider — 1.00× = unchanged, below 1 = slower, above 1 = faster.
  3. Set the pitch slider in semitones — 0 = unchanged, +12 = octave up, -12 = octave down.
  4. Optionally tick 'Link speed & pitch' for vinyl-style behaviour (speed and pitch move together).
  5. Pick an output format and click 'Process & Download'.
  6. Audition the result in the inline player, then download.

When to use Audio Speed & Pitch Changer

  • Slowing a guitar solo to half speed (without changing key) for transcription
  • Speeding up a podcast 1.25× without chipmunk-pitch artifacts
  • Transposing a karaoke backing track up or down a few semitones
  • Pitch-shifting a sound effect by an octave for sound design
  • Vinyl-style speed-up effect (DJ-style pitching) on a sample
  • Creating a slowed + reverb-style fan edit (combine with a reverb plugin)

Examples

Transcribe a guitar solo

Input: MP3 of solo at 1.00× speed

Output: MP3 at 0.5× speed, same key — slow enough to learn note-by-note

Faster podcast

Input: M4A episode at 1.00×

Output: M4A at 1.25× speed, original pitch — finish faster, no chipmunk

Vinyl pitch-down

Input: Track at original speed (linked mode on)

Output: Track 7% slower and a half-step lower, like a DJ slowing the platter

Tips

  • atempo natively only handles 0.5–2× speed; this tool chains multiple atempo passes so values down to 0.25× and up to 4× still work cleanly.
  • Pitch shifts of more than ±5 semitones start sounding artificial. For larger transpositions, iterate or use a dedicated tool with formant correction.
  • Linked mode = vinyl. Unlinked mode = each control is independent. The two are different effects entirely.
  • Slowing audio to half speed roughly doubles the file length (and the file size for lossless outputs).
  • Combine speed and pitch shifts in one pass rather than running the tool twice — quality is better with a single re-encode.

Frequently Asked Questions

Can I change speed without changing pitch?
Yes — that's the default. atempo time-stretches without affecting pitch.
Can I change pitch without changing speed?
Yes — leave the speed slider at 1.00× and move only the pitch slider. asetrate + aresample + a compensating atempo pass handle this.
What's the difference between linked and unlinked?
Unlinked: speed and pitch are independent (modern DAW-style). Linked: speeding up raises pitch (vinyl-style). Both are useful — pick by the effect you want.
Why is the maximum 4× speed?
Beyond about 4×, atempo artifacts (transient smearing) become very obvious. Higher values are theoretically possible but don't sound musical.
Does this use any AI or fancy pitch correction?
No — it uses ffmpeg's classic time-domain time-stretch (atempo) and sample-rate-based pitch shift. Works for most material; very large pitch shifts will sound artificial.
Will the file size change?
Yes. Slowing audio makes it longer (bigger file at the same bitrate); speeding up makes it shorter.
Are my files uploaded?
No. ffmpeg.wasm runs locally in your browser; the file never leaves your device.
Why do extreme pitch shifts sound 'chipmunky' or 'demonic'?
asetrate-based pitch shifting also stretches formants. Real instruments and voices have pitch-independent formant structure; without formant correction, big shifts sound unnatural.

Explore the category

Glossary

atempo
ffmpeg audio filter that changes playback speed without changing pitch. Native range is 0.5×–2×; this tool chains multiple to extend that.
asetrate
ffmpeg filter that changes the sample rate metadata, scaling pitch and tempo together.
aresample
ffmpeg filter that resamples audio back to a target sample rate. Used after asetrate to normalise the output.
Semitone
A musical interval — 12 semitones make an octave. +1 semitone is a small upward pitch shift; +12 doubles the pitch.
Time-stretching
Changing audio speed without changing pitch. Achieved here via atempo.
Pitch-shifting
Changing audio pitch without changing speed. Achieved here via asetrate + aresample + atempo compensation.