Free Online Tempo Changer
Speed up or slow down audio, pitch intact.
Drag & drop your audio file here
or
Max file size: 100 MB · MP3, WAV, FLAC, OGG
Original
beats per minute
musical key
100% is normal speed. Lower values slow down, higher values speed up - pitch stays the same.
Processing…
Result
How it works
The Tempo Changer stretches or squeezes audio in time without touching its pitch, using a time-stretching algorithm applied to every channel. Set 50% to halve the speed for transcription or practice, or 150% to breeze through a lecture - the musical key stays exactly where it was.
Optionally, the rendered result can be passed through a studio-quality convolution reverb, with seven rooms from tight bathroom to vast cathedral and a wet/dry mix control. That combination is what creates the viral "slowed + reverb" sound in a single click.
This is a buffer (offline) tool: the entire file is rendered with your settings and returned as a downloadable file. Everything runs client-side in your browser, so your files never leave your device.
Frequently asked questions
Does changing the tempo change the pitch?
No. Slowing to 50% makes the song last twice as long but keeps every note at its original pitch - unlike simply playing a record slower. Speeding up to 150% keeps voices natural instead of chipmunk-like.
What is the slowed-and-reverbed preset?
It renders the audio at 80% speed with a medium-room convolution reverb blended in - the hazy, atmospheric aesthetic popularized by slowed-and-reverbed edits on social media.
What tempo range is supported?
From 25% (quarter speed) to 200% (double speed), in 1% steps. Extreme slowdowns on long files take longer to render.
Is there a file size limit? Is it private?
Files up to 100MB are supported. Rendering happens entirely in your browser - your audio never leaves your device.