Audio Speed Changer — 0.25x to 4x, Preserve Pitch
Speed up or slow down any audio file with our free browser-based speed changer. Adjust playback from 0.25x to 4x with the option to preserve the original pitch. Perfect for learning music by ear, transcribing interviews, speed-listening to podcasts, or creating audio effects.
Pitch preservation is what separates a usable speed change from a novelty. Without it, playing at 1.5x also lifts every frequency by half again and a speaker turns into a chipmunk; with it, only the timing moves. The practical ranges: 1.25-1.5x for podcasts and lectures on a subject you already know, and 0.5-0.75x for transcribing an interview or working a guitar part out by ear.
How to use Audio Speed Changer
- Upload your audio file (MP3, WAV, OGG, FLAC).
- Use the slider to adjust speed from 0.25x to 4.0x.
- Leave "Keep the original pitch" ticked to avoid the chipmunk or deep-voice effect, or untick it for a slowed or nightcore sound.
- Click Apply Speed Change, preview the result, then download it as an MP3.
Features
- Speed options — Range from 0.25x (quarter speed) to 4x (quadruple speed).
- Preserve pitch option — Change the speed while keeping the natural tone intact.
- Real-time playback preview — Listen and experiment before committing.
- Multiple format support — Easily process MP3, WAV, OGG, FLAC, and M4A.
Frequently Asked Questions
Can I speed up audio without changing pitch?
Yes. Keep "Keep the original pitch" ticked and the audio plays faster or slower without the chipmunk or deep-voice effect. It uses FFmpeg's atempo filter, which stretches time without shifting frequencies, running in your browser.
How much can I speed up or slow down audio?
Our tool supports speeds from 0.25x (4 times slower) to 4x (4 times faster). Use 1.5x-2x for podcasts and lectures, 0.5x-0.75x for learning music by ear.
Is my audio file kept private?
Absolutely. Our speed changer processes everything in your browser. Your audio file is never uploaded to any server — it stays on your device from start to finish.
Which speed should I actually use?
For speech, 1.25x is comfortable almost immediately and 1.5x takes about a week to get used to. Past 2x, comprehension drops sharply for most people even though the audio is still perfectly clear. For learning music, 0.5x keeps enough pitch definition to hear individual notes while giving you time to find them.
Is the downloaded file actually shorter?
Yes. The export is the real duration at the new speed, not the original with a playback flag attached. A 60-minute lecture at 1.5x downloads as a 40-minute file that plays at normal speed in any player, including car stereos and offline apps that ignore speed settings.