Change Audio Speed and Pitch

Speed up or slow down audio without changing the pitch, change the pitch, or reverse it, in your browser. Free, no sign-up, nothing uploaded.

Runs in your browser. Your files are never uploaded. How it works

Change Audio Speed speeds up or slows down audio without changing the pitch, changes the pitch without changing the speed, or plays it backwards. Use it for lectures and podcasts at 1.5×, practising music at 0.75×, changing the key of a song, or making a nightcore or slowed version.

How to change the speed

  1. Choose an audio file or a video.
  2. Pick the Speed (0.5× to 2×) and, if you like, the Pitch in semitones (−12 to +12).
  3. Leave Keep pitch when the speed changes on for natural voices; tick Play backwards to reverse it.
  4. Click Apply, listen to the preview and download as MP3, WAV, M4A, FLAC or OGG.

Speeds and what they are good for

Speed 60 minutes becomes Good for
0.5× 120 min Transcribing by hand, learning a fast solo
0.75× 80 min Practising an instrument, language learning
0.9× about 67 min Following a fast speaker
1.25× 48 min Podcasts, audiobooks
1.5× 40 min Lectures, recorded meetings
2× 30 min Skimming a recording

0.8×, 1.1× and 1.75× are in the list too.

Keep pitch on or off

With Keep pitch on (the default), the audio is time-stretched: it is played in short overlapping slices that are placed so the waves line up, which keeps voices at their normal pitch. This works very well for speech and solo instruments. Dense music at extreme speeds such as 0.5× or 2× can sound slightly wobbly or echoey.

With Keep pitch off, the audio plays like a record or tape running faster or slower: the pitch rises and falls with the speed, and the Pitch setting is not used. That is the sound of sped-up and slowed song versions.

  • Nightcore: 1.25× with Keep pitch off. Higher and faster.
  • Slowed: 0.8× with Keep pitch off. Deeper and slower.
  • Change the key only: speed 1×, pitch up or down in semitones. See Change Pitch.
  • Backwards: tick Play backwards. See Reverse Audio.
  • Practice track: 0.75× with Keep pitch on, so the song stays in tune with your instrument.

Tips

  • Long files take a little while to stretch; the progress bar shows how far it is, and Cancel stops it.
  • If you will edit the result again, save as WAV or FLAC to avoid an extra lossy save.
  • To speed up only part of a recording, cut that part out first with the Audio Cutter.

Private by design

Your files are processed on your own device and never uploaded. See how it works.

Frequently asked questions

Is my audio uploaded?

No. The audio is processed in your browser, on your device, and never sent anywhere.

Can I speed up without the chipmunk voice?

Yes. Keep pitch when the speed changes is on by default: voices sound normal at 1.5× or 2×.

How do I change the key of a song?

Leave the speed at 1× and choose the pitch in semitones: +2 is one whole tone up, −12 one octave down.

What about sped up or slowed versions of songs?

Turn Keep pitch off: the audio then plays like a faster or slower record, with the pitch going up or down with the speed.

How long will the new file be?

The original length divided by the speed: a 60-minute lecture at 1.5× lasts 40 minutes, a 3-minute song at 0.75× lasts 4 minutes. A pitch change alone keeps the length.

More ways to use Change Audio Speed

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