Audio Speed Changer — Free Online

Change the playback speed of any audio file. Speed up or slow down without changing pitch.

Tus archivos se eliminan aproximadamente una hora después

Speeding up a podcast to get through it faster, slowing down a music recording to learn a difficult passage, or changing playback rate for language study — these are all common needs that most media players handle only at a system level and with limited control. When you need to export a file at a different speed for sharing or further editing, a dedicated tool is essential.

This speed changer lets you set any playback rate — from half speed up to double — and exports the result as a new audio file. Crucially, it adjusts speed without changing pitch, so a voice recording sped up by 50% still sounds natural, not chipmunk-like.

How to Change Audio Speed Online

  1. 1

    Upload your audio file

    Drop any MP3, WAV, FLAC, OGG, or AAC file. Files up to 100 MB are supported.

  2. 2

    Set the speed multiplier

    Enter a speed factor: 0.5× for half speed (slower), 2× for double speed (faster). Pitch is optionally preserved.

  3. 3

    Download your speed-adjusted audio

    Click Apply. FileCrank adjusts the playback speed and exports your audio. Files are deleted within 1 hour.

How Time-Stretching Without Pitch Shift Works

Changing audio speed without altering pitch is a non-trivial signal processing problem. Simply resampling the audio changes both speed and pitch proportionally, producing the classic chipmunk or slow-motion effect. Time-stretching avoids this by using a phase vocoder algorithm: the audio is decomposed into short overlapping frames via a Short-Time Fourier Transform, the frames are redistributed across time at the target rate, and the signal is reconstructed with phase continuity maintained.

The tool uses the SoundTouch library compiled to WebAssembly, which implements an optimised phase vocoder with transient detection to reduce the smearing artefacts that naive implementations produce on percussive material. The result is natural-sounding tempo adjustment across a wide speed range.

Why Use FileCrank to Change Audio Speed?

  • ✓ Speed up or slow down audio by any factor from 0.5× to 4×.
  • ✓ Option to preserve or change pitch when adjusting speed.
  • ✓ Supports MP3, WAV, FLAC, OGG, and AAC input.
  • ✓ No watermarks, no signup, completely free.
  • ✓ Files are processed securely and deleted within 1 hour.

Características y Especificaciones

Tamaño máx. de archivo
Hasta 100 MB
Privacidad
Archivos eliminados tras aproximadamente una hora
Precio
Gratis, sin registro
Procesamiento
En el servidor
Archivos eliminados en 1 hora — automáticamente.No se requiere registro.Gratis — sin cargos ocultos.

Frequently Asked Questions

What speed range is supported?

You can speed up audio to 4× or slow it down to 0.25× of the original speed.

Will the pitch change when I change speed?

By default, speed change also changes pitch (like a tape). Enable pitch correction to keep the original pitch at a different speed.

What formats are supported?

MP3, WAV, FLAC, OGG, and AAC input files are supported.

Time-Stretch Tool vs Player Speed Controls

Media players like VLC offer speed controls, but they affect only playback — you cannot export the result. Audacity's Change Tempo effect requires installation and a manual export workflow. This tool provides the same high-quality time-stretching algorithm in a browser interface and exports the altered file directly, with no installation needed.

FileCrank Audio Speed Changer adjusts playback speed of any audio file with optional pitch correction. Supports MP3, WAV, FLAC, OGG, and AAC. Free, no signup, files deleted within 1 hour.

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