A LITTLE HELP. A LOT DONE.
Good tools.
Great flow.

Your shortcut to the everyday. Create, convert, calculate,
and get back to what you love.

✓ Free to use✓ No sign-up✓ 500+ possibilities
Audio

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.

Loading interactive tool…

About this tool

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 it

  • 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

  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 it helps

  • 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

Expected result

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

Faster podcast

Input

M4A episode at 1.00×

Expected result

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

Vinyl pitch-down

Input

Track at original speed (linked mode on)

Expected result

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 adjust 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

Audio Compressor Shrink MP3, WAV, M4A, OGG and FLAC files by re-encoding at a lower bitrate. Choose 32–320 kbps, pick MP3, OGG or M4A output, then download. 100% browser-side via ffmpeg.wasm. Audio Format Converter Convert audio between MP3, WAV, OGG, M4A and FLAC in your browser. Choose bitrate or sample rate, then download. Runs locally via ffmpeg.wasm — no uploads. Audio Loudness Normalizer (LUFS) Normalize loudness of MP3, WAV, M4A, OGG and FLAC files using ffmpeg loudnorm (EBU R128). Hit Spotify, podcast or broadcast targets — runs locally via ffmpeg.wasm. Audio Reverser Reverse any audio file so it plays backwards. Drop MP3, WAV, M4A, OGG or FLAC, choose output format, and download. ffmpeg.wasm areverse — no upload. Audio Merger Concatenate multiple MP3, WAV, M4A, OGG or FLAC files into one continuous audio track. Drag to reorder, set output format and bitrate, then download. MP3 Cutter & Audio Trimmer Trim or cut uploaded audio with draggable waveform handles, precise preview, undo, and exports to WAV, MP3, M4A, OGG, or FLAC.
Why Browser Vocal Removers Sound Worse Than AI Tools (And When That's OK) A free browser vocal remover does center-channel cancellation in ten lines of JavaScript. An AI tool runs a neural network trained on tens o Apr 2026 · 9 min How BPM Detection Algorithms Find the Beat Tempo detection sounds easy until you try it. From onset detection to autocorrelation and modern neural beat trackers, we walk through how c Mar 2026 · 9 min

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.