notevibes. Free Browser BPM Changer

Change a song’s tempo to any BPM

Detect the current tempo, type the BPM you want, and retempo the track — pitch preserved. Free, with the stretch running in your browser. Perfect for beatmatching, mashups, and practice.

Only the BPM read touches our server — the retempo runs in your browser and the audio is discarded after.
Auto-detect the current BPM
Pitch preserved
MP3 & WAV output
Works on mobile
How it works

How to Change a Song’s BPM

Three steps — we detect the tempo, you pick the new one.

1

Upload a Song

Drop any track, up to 200 MB — MP3, WAV, M4A, FLAC, OGG, or AAC. We detect its current BPM automatically.

2

Enter the Target BPM

Type the tempo you want; we compute the exact stretch from the detected BPM. Fix the detected value by hand if it looks off.

3

Preview & Download

Hear it at the new tempo right in your browser, then download the retempo'd track as MP3 or WAV.

Why Notevibes

Why Notevibes BPM Changer

Type the exact tempo you want — no multipliers, no chipmunk pitch.

Type a Target BPM

We auto-detect the song's current tempo the moment you drop it, so you just enter the BPM you want — no guessing stretch multipliers.

Pitch Stays Natural

Time-stretching keeps the original pitch, so voices and instruments sound right at any tempo — no chipmunk, no muddy slow-down.

Made for DJs & Dancers

Match two tracks for a mashup, beatmatch a set, or slow a song down to learn the moves or the parts note for note.

Preview Before You Save

The retempo runs in your browser and plays back instantly, so you can hear the new tempo before downloading an MP3 or WAV.

Read, Then Gone

The song is sent once to read its tempo, then discarded — the retempo itself happens in your browser and is never uploaded.

Finish in the Editor

Want to change the key too, trim, or add effects? Open the result in the AI editor and just describe the edit.

Read for the Beat, Then Gone

Your song is sent once, only to read its tempo, and discarded right after — nothing is stored. The retempo itself runs on your own device and never leaves your browser.

Read, Not Kept

The tempo read is discarded immediately

No Account

Start changing tempo immediately

Retempo Local

The stretch happens in your browser

Made for

What People Retempo

One tool for every “this needs to be at a different tempo” moment.

Beatmatch a Set

Nudge two tracks to the same BPM so they mix cleanly

Build a Mashup

Line up the tempo of two songs before you layer them

Dance Practice

Slow a track down to learn the choreography, then speed it back up

Learn an Instrument

Drop the tempo to catch every note, then work back to full speed

Workout Tempo

Retempo a playlist to match your running or cycling cadence

Backing Tracks

Match a karaoke or practice track to a comfortable tempo

The Tempo Change That Doesn’t Wreck the Pitch

Most free ways to change a song’s tempo make you do the math — guess a “1.15×” multiplier and hope — or they speed the track up and turn every voice into a chipmunk. You don’t want a multiplier; you want a number. This tool detects the song’s current BPM for you, lets you type the exact tempo you’re after, and stretches to it while keeping the pitch dead-on.

Type the BPM, not a guess

Drop a track and its current tempo is read automatically — powered by Essentia, the same open detection engine behind many DJ tools — so you never have to count it out. Enter your target BPM and the exact stretch is computed for you, anywhere from a quarter speed up to 4× faster. If the detection misreads a tricky track, you can type the real tempo in by hand and the stretch recalculates.

Private where it counts

The one thing that leaves your device is a quick read to detect the tempo, and that copy is discarded right after — nothing is stored. The retempo itself, the part that touches the actual audio, runs entirely in your browser and plays back before you commit. Download an MP3 to share or a WAV to keep working with.

When you need more than tempo

Just want the number without changing anything? The BPM detector reads tempo, key, and Camelot code from a file, and the BPM tapper finds it by ear. To also change the key, trim, or clean up the track, open it in the online audio editor.

Need to Change the Key Too?

The full Notevibes editor shifts key, retempos, cleans up, and applies AI tools to your track — then exports to MP3 or WAV.

Free to try · No credit card required

Keep going

Related Audio Tools

More free AI audio tools from Notevibes — same engine, no sign-up.

FAQ

BPM Changer FAQ

How do I change the BPM of a song?

Drop the song in — we detect its current BPM automatically — then type the target BPM. We time-stretch the track to the new tempo while keeping the pitch the same, and you preview and download the result.

Does changing the BPM change the pitch?

No. Only the tempo changes; pitch is preserved, so voices and instruments stay natural with no chipmunk effect. If you also want to shift the key, do that in the AI editor.

Is my song uploaded to a server?

Only briefly, and only to read the tempo. When you drop a file it's sent once to detect its current BPM, then discarded — the retempo itself runs in your browser and is never uploaded. Nothing is stored.

How much can I speed up or slow down?

Up to 4× faster or down to a quarter of the original tempo. Very large changes can introduce some stretching artifacts.

What if the detected BPM looks wrong?

You can edit the “current BPM” field by hand — the target stretch recomputes from whatever you set, so a misread detection is easy to correct.

What formats can I use?

MP3, WAV, M4A, FLAC, OGG, and AAC in, up to 200 MB. You can download the result as MP3 or WAV.

Is it free?

Yes — the BPM Changer is free to use. There's no account, no watermark, and no daily cap.