Audio Speed Changer

Slow down or speed up a song, keep its key or let the pitch follow, and add reverb. Hear it before you save. The file stays on your device.

How to change the speed of a song

Three steps, in the browser.

Choose a song

Drop an audio or video file of up to 2 GB: MP3, WAV, M4A, FLAC, MP4 and more.

Set the speed and listen

Move the slider from 0.25× to 3× or tap an effect. Choose whether the pitch stays or follows, add reverb, and play the preview.

Save it

Download MP3, WAV or M4A, or send the result to the audio trimmer or the BPM finder.

Which speed for what

Keep the pitch to practise or listen faster; let it follow for the slowed and nightcore sound.

0.5×	Transcribing a fast solo note by note.	−12 st
0.75×	Playing along while learning a part.	−5 st
0.8×	Slowed + reverb: lower, slower, with a room around it.	−3.9 st
1.25×	Nightcore and sped-up: higher and faster.	+3.9 st
1.5×	Listening to talks, lectures and podcasts faster.	+7 st

Right column: the pitch change in semitones (st) when the pitch follows the speed.

What the speed changer does

From 0.25× to 3×

In steps of 0.05, with presets for half speed, three quarters and the usual speed-ups.

Keep the key or not

Keep the pitch (time stretching) to practise in the original key, or let the pitch follow the speed like a record.

Slowed + reverb and nightcore

One tap sets the speed, the pitch and the reverb for the slowed, nightcore or practice sound; adjust from there.

Preview before saving

Play the song at the new speed, with the reverb, while you move the sliders. Saving uses the same settings.

Length and pitch shown

The page shows the new length and how many semitones the pitch moves, before you save.

Stays on your device

The file is processed in your browser. Nothing is uploaded, there is no account and no daily limit.

Speed changer FAQ

Pitch, slowed + reverb, formats and privacy.

How do I slow down a song without changing the pitch?

Choose the song, keep Keep the pitch selected and move the speed slider below 1× (0.75× is a common practice speed). Play the preview, then press Change the speed and download it.

How do I make a slowed + reverb version?

Tap Slowed + reverb: the speed goes to 0.8×, the pitch follows the speed (about 3.9 semitones lower) and reverb is added. Adjust the speed and the reverb to taste, listen in the preview, and save.

How do I make a nightcore or sped-up version?

Tap Nightcore: 1.25× with the pitch following, about 3.9 semitones higher. For a faster version that stays in the original key, choose Keep the pitch instead.

What is the difference between keeping the pitch and letting it follow?

Keeping the pitch stretches the time, so the song is slower or faster in the same key. Letting the pitch follow plays it like a record at another speed: slower is lower, faster is higher.

How slow or fast can it go?

From 0.25× to 3×. Time stretching sounds most natural between about 0.5× and 1.5×; at extreme speeds you hear more artefacts.

Which formats can I open and save?

Most audio and video files up to 2 GB open, including MP3, WAV, M4A, FLAC, OGG and MP4. You can save MP3 (192 kbps), WAV (up to 30 minutes of result) or M4A.

Are my files uploaded? Is it free?

No upload: the audio engine (ffmpeg) is downloaded once and runs in your browser, so the file never leaves your device. It is free and needs no account.

Can I find out the name of a slowed or sped-up song?

Yes. If you know how it was changed, set the opposite speed here (a song slowed to 0.8× with the pitch following comes back at 1.25×), then press Identify this song. The song finder's hum and cover mode can often recognise pitched versions too.