Audio Tempo Changer Online
Speed up or slow down any audio while keeping the pitch exactly the same — no chipmunk, no tape-stop. Drop a file, pick a tempo, preview, download. No sign-up, and your file is never uploaded.
How to Change Audio Tempo
No account, no upload — three steps on your own device.
Drop Your Audio
MP3, WAV, M4A, FLAC, OGG, or AAC up to 200 MB. It decodes right in the browser.
Pick a Tempo
Tap 0.5× to 2×. The new duration is shown live, and pitch stays the same at every tempo.
Change & Download
Hit Change Tempo, preview the result, and download the MP3 at the bitrate you want — no queue, no watermark.
Why Notevibes Tempo Changer
A true time-stretch — the tempo moves, the pitch doesn’t.
Five Tempo Presets
0.5×, 0.75×, 1.25×, 1.5×, and 2× — one tap each, with the new duration shown before you commit.
Pitch Stays Put
Voices and instruments keep their natural key at every tempo — no chipmunk, no tape-stop drag.
Never Uploaded
The time-stretch runs entirely in your browser. Your file never leaves your device — there is nothing to delete because nothing was sent.
Every Common Format
MP3, WAV, M4A, FLAC, OGG, AAC — anything your browser can decode loads, up to 200 MB.
Preview, Then Download
Listen to the stretched result before you commit, then download an MP3 at the bitrate you choose — 64 to 320 kbps.
Free, Anywhere
No watermark, no sign-up, no daily limits. Works on phones, tablets, and laptops in any modern browser.
Nothing to Upload, Nothing to Leak
The time-stretch happens on your own device. Your file never touches a server — which is a stronger promise than any “we delete it later”.
No Upload
Decoding and stretching run on your device
No Account
Start changing tempo immediately
Works Offline
Once the page loads, no connection needed
When to Change Tempo
One tool for every “this is the right key, wrong speed” moment.
Faster Audiobooks
Listen at 1.25× or 1.5× without the narrator sounding sped-up
Faster Podcasts
Cut listening time without turning voices into chipmunks
Slow Solos to Learn
Drop a track to 0.75× or 0.5× to learn a riff or solo by ear
Lecture Playback
Speed through dense lectures, slow down the tricky passages
Fit a Voiceover to Video
Stretch narration to fill the exact length of a cut
Pacing Rehearsal
Practice along at a slower tempo, then bring it back up to speed
Change the Speed, Keep the Voice
Slowing a song down to learn a part the naive way turns it into a low, sludgy mess; speeding a lecture up the same way makes everyone sound squeaky. Both happen because a simple speed change ties pitch and tempo together. A tempo changer breaks that link — it stretches or compresses the timeline while leaving the pitch exactly where it was, so a slowed guitar solo stays in tune and a sped-up narrator still sounds human.
Time-stretch, not resample
Tempos near 1× are essentially transparent — 0.75× and 1.25× are the everyday sweet spot for practice and faster listening. Push to 0.5× or 2× and you’ll hear slight smearing on sharp transients like drums, but speech stays perfectly clear. It runs SoundTouch, the same time-stretch engine behind many DJ and practice apps. If you don’t know the track’s tempo or key to begin with, the BPM & key detector will tell you first.
Private by physics, not by promise
Most online tempo tools make you upload the file and wait for a server. This one never receives it — the audio is decoded, stretched, and re-encoded on your own device. That’s why it’s free with no watermark or daily cap: there’s no server bill to pass on to you.
Speed, pitch, or tempo — pick the right tool
This page changes tempo only, keeping the key. If you want the classic coupled effect where speed and pitch move together — nightcore, slowed + reverb — that’s the audio speed changer. If you want the opposite, changing the key while the timing stays put, use the audio pitch changer. For stacked operations — tempo plus pitch plus EQ on one track — open the online audio editor.
Need Tempo and Pitch Together?
The full Notevibes editor stacks tempo change with pitch shift, voice effects, EQ, and AI cleanup — then exports to MP3 or WAV.
Free to try · No credit card required
Related Audio Tools
More free AI audio tools from Notevibes — same engine, no sign-up.
Audio Pitch Changer
Shift pitch up or down without changing duration.
Audio Speed Changer
Speed up or slow down audio from 0.5x to 2x.
Voice Changer
Chipmunk, helium, deep, giant, or demon voice effects.
Audio Reverser
Play any audio file backwards.
Audio Normalizer
Boost audio to peak volume without clipping.
MP3 Editor
Full MP3 editor with timeline, effects, and export.
Audio Tempo Changer FAQ
Is my audio uploaded to a server?
No. The tempo changer runs entirely in your browser — the file is decoded, time-stretched, and re-encoded on your own device. Nothing is transmitted, so there is nothing for us to store or delete.
What is a tempo changer?
A tempo changer (also called a time-stretcher) speeds up or slows down audio without changing its pitch. The audio takes more or less time to play, but voices and instruments stay in their original key — no chipmunk, no tape-stop.
How is this different from a speed changer?
A speed changer plays audio faster or slower by resampling, which drags pitch along with it — faster sounds like a chipmunk, slower sounds like tape-stop. A tempo changer moves only the duration and keeps the pitch locked. To change the key while keeping the timing, use the audio pitch changer instead.
Will the stretched audio sound natural?
Tempos near 1× are essentially transparent — 0.75× and 1.25× sound clean. At 0.5× and 2× you may notice slight smearing on sharp transients like drums and plosives, but speech stays clearly intelligible.
What formats are supported?
MP3, WAV, M4A, FLAC, OGG, and AAC up to 200 MB — anything your browser can decode will load. The result downloads as an MP3 at the bitrate you pick, from 64 to 320 kbps.
Is the tempo changer free?
Yes — completely. Because the processing runs on your device rather than our servers, there is nothing to meter: no watermark, no sign-up, no daily limits.
Does it work on my phone?
Yes — iOS and Android browsers included. Long files stretch faster on a laptop simply because the processor is faster, but the tool is the same.