Quick answer
To change audio speed online, load your track into the Audio Speed Changer, adjust the Speed slider between 0.50× (half speed) and 2.00× (double speed), preview the result in real time, and export the adjusted MP3 or WAV. No uploads, watermarks, or account needed.
How to use the Speed Changer
- Load your audio fileOpen any song, lecture, interview, or instrumental practice track.
- Adjust the Speed sliderSlide right to speed up (e.g., 1.25×, 1.5×) or left to slow down (0.75×, 0.5×).
- Preview tempoPress Space or Preview result to hear the adjusted tempo immediately.
- Download the modified trackExport as MP3 or WAV with new duration calculated automatically.
Popular speed settings
- 0.75× – 0.85×: Great for transcribing interviews, learning guitar solos, or learning dance choreography.
- 1.15× – 1.25×: The sweet spot for podcasts and audiobooks — completely natural speech flow while saving 15–20 minutes per hour.
- 1.50× – 1.75×: Fast-forwarding dense academic lectures, meeting recordings, and voice messages.
- Nightcore / Daycore: Speeding up pop music to 1.25×–1.35× creates the viral TikTok Nightcore sound effect!
Everything you can do
Cut & trim
Sample-accurate cuts with draggable handles and millisecond time inputs.
Remove a section
Delete the middle of a recording and join the rest seamlessly.
Fade in / out
Smooth 0–10 s fades so clips never start or end with a click.
Volume & speed
Boost quiet audio up to 300% and change tempo from 0.5× to 2×.
Private by design
Runs entirely in your browser. Files are never uploaded or stored.
Instant export
MP3 encoding in a background thread — the page never freezes.
Frequently asked questions
Does changing speed affect the total file duration?
Yes. Speeding up to 1.50× shortens the total duration by 33%, while slowing down to 0.75× lengthens it by 33%. The output duration is updated live on screen.
Can I speed up just one part of the song?
Yes. Select the region on the waveform, set your speed, and click Cut & export.
Is MP3 Cutter really free?
Yes. Every feature — cutting, fading, volume, speed and MP3/WAV export — is free with no sign-up, no watermark and no daily limit. The site is supported by unobtrusive ads.
Are my files uploaded to a server?
No. Your audio is decoded and processed entirely inside your browser using the Web Audio API and an MP3 encoder that runs locally. The file never leaves your device, so it works even for private recordings.
Does it work on iPhone, Android and Chromebook?
Yes. MP3 Cutter runs in any modern browser — Safari on iPhone/iPad, Chrome on Android, Chrome OS, Windows, macOS and Linux. No app install is required.
Last updated · by MP3 Cutter Team