Audio Speed Changer

Change audio playback speed from 0.25x to 4x while preserving pitch. Speed up podcasts, slow down music for practice, or adjust pacing of audio content. Uses FFmpeg's atempo filter for natural-sounding results.

What is it used for?

Speeding up podcasts and audiobooks for faster listening
Slowing down music for practice and learning
Adjusting interview audio pacing
Creating speed-adjusted versions of audio content

Step-by-Step Guide

Upload your audio file
Adjust the speed slider (0.25x to 4x) or click a preset button
Click 'Convert to .MP3'
Preview the speed-adjusted audio
Download the result

How it works

Upload an audio file, adjust the speed slider, and click Convert. FFmpeg's atempo filter changes the tempo while preserving pitch. For speeds outside 0.5x-2x, multiple atempo filters are chained.

Tips & Best Practices

1.5x is popular for podcasts and audiobooks
0.75x is good for music practice
Use 2x for quickly reviewing long recordings

Frequently Asked Questions

Is the pitch preserved?

Yes, the atempo filter changes speed without altering pitch. A sped-up voice still sounds natural, not chipmunk-like.

What's the maximum speed?

Up to 4x. At very high speeds, speech becomes hard to follow but music remains recognizable.

Privacy & Security

This tool uses FFmpeg compiled to WebAssembly (WASM). The WASM binary (~25MB) is downloaded from a CDN on first use and cached by your browser. All file processing happens locally on your device - your files are never uploaded to any server. This makes it safe for sensitive, private, or confidential media files. Large files may take longer to process depending on your device's CPU and available memory.

Audio Speed Changer

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