Speed Up Audio
Listen Faster Without the Chipmunk Effect
Need to use Speed Up Audio right now?
From 0.25x up to 4x, with automatic chaining beyond the tempo filter's normal 0.5x-2x range.
Drop an audio file, or click to browse
Processed locally in your browser — never uploaded
Changes playback speed while keeping pitch natural — useful for speeding through a lecture or slowing down music to learn a part, without the chipmunk or slow-motion pitch shift.
Features
- Runs entirely in your browser
- Privacy-first — your data is never uploaded
- Real-time, instant results
- 100% free, no sign-up required
- Works on desktop, tablet, and mobile
- No installation needed
Who uses this tool?
About Speed Up Audio
Listening to a long lecture or podcast faster, or slowing down a piece of music to study a part more closely, both require changing playback speed while keeping the pitch natural — speeding up raw audio samples directly would raise the pitch (the classic chipmunk effect), and slowing down would drop it unnaturally. This tool uses FFmpeg's dedicated tempo-adjustment filter to change speed while keeping pitch exactly where it started.
A real FFmpeg build compiled to WebAssembly performs the speed change entirely inside your browser using the atempo filter, which intelligently resamples the audio to alter playback speed independently of pitch — genuinely different from simply changing the sample rate, which would tie speed and pitch together.
FFmpeg's tempo filter is only rated for factors between 0.5x and 2x in a single application, so for more extreme speed changes (very fast or very slow), this tool automatically chains multiple tempo adjustments together to reach the overall requested factor while each individual step stays within the filter's valid range.
The result is re-encoded as MP3 at the new speed, with pitch sounding exactly as natural as the original recording — useful for anything from podcast binge-listening at 2x to slowing down a musical passage to half speed for learning.
How it works
- Upload your audio file. The file loads into the browser-based FFmpeg engine.
- Set the speed multiplier. From 0.25x (quarter speed) to 4x (four times faster).
- Apply and download. Speed changes; pitch stays exactly natural.
Examples
Speeding through a long podcast episode
Input
60-minute episode, 1.5x speed
Output
a 40-minute file, pitch unchanged