Change Audio Speed Online

Speed a track up or slow it down, then download the retimed file. Built for lecture recordings, practice loops, and audiobook pacing.

Drop a file or click to upload

How to use

  1. Drop the audio file you want retimed.
  2. Enter a speed multiplier, for example 1.5 or 0.75.
  3. Click Process and download the retimed track.

Frequently asked questions

Does speeding it up raise the pitch?

No. The atempo filter stretches time and leaves pitch alone, so a lecture at 1.5x still sounds like the same person rather than a chipmunk.

What is the useful range?

Roughly 0.5x to 2x in one pass. Beyond that the time-stretch starts to smear consonants, and the artefacts are more distracting than the time saved.

Does the file get shorter?

Yes, proportionally. A 60 minute recording at 1.5x comes out at 40 minutes, and the file size drops by about the same fraction.

Can I slow something down to transcribe it?

That is what values below 1 are for. Around 0.75x is usually enough to catch a fast speaker without the audio starting to sound underwater.

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