Audio Speed Changer
Speed up or slow down audio files online for free. 0.25x to 2x with optional pitch-preserving time stretch via Web Audio, in-page preview and WAV download - no upload required.
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What is Audio Speed Changer?
The Audio Speed Changer resamples or time-stretches audio files directly in your browser with the Web Audio API. Choose any speed from 0.25x to 2x, optionally preserve the original pitch with an overlap-add time-stretcher, preview the processed result in the page, and download it as a WAV file - with no upload at any point.
Key Benefits
- Fast-forward through long recordings without chipmunk voices
- Slow down fast speech until every word is clear
- Optional pitch preservation with overlap-add stretching
- In-page preview before you commit to a download
- Private by design - audio never leaves your machine
Common Use Cases
- •Speeding through lecture recordings and podcasts
- •Slowing down language-learning audio for practice
- •Adjusting demo audio to fit a video timeline
- •Turning any audio into a slower practice loop for music
How to Change Audio Speed
- Choose the audio: Select an MP3, WAV, OGG or M4A file from your device.
- Set the speed: Move the slider between 0.25x and 2x and choose whether to preserve pitch.
- Process and preview: Press Process audio, then listen to the result right on the page.
- Download the WAV: Save the processed audio as a WAV file playable anywhere.
Key Features
- Speed range from 0.25x up to 2x
- Optional pitch preservation via overlap-add time stretch
- Web Audio offline rendering for fast processing
- In-page preview of the processed audio
- WAV export playable anywhere
- No upload - audio stays on your machine