Does changing the speed keep the pitch?

Yes. Sondra uses a tempo filter that changes the speed while keeping the pitch natural, so the voice or music still sounds right.

Is my audio uploaded to a server?

Never. Everything runs locally in your browser. Your file never leaves your device.

How slow or fast can I go?

You can choose from 0.25x (four times slower) up to 4x (four times faster), including 0.5x, 0.75x, 1.5x and 2x.

Which audio formats are supported?

You can change the speed of MP3, WAV, AAC, FLAC, M4A and OGG files.

Yes. Changing audio speed on Sondra is free, with no signup and no watermark.

Can I change audio speed on my phone?

Yes. Sondra works in mobile browsers, with files up to 100MB on mobile and 500MB on desktop.

Will speeding up make voices sound squeaky?

No. Because the pitch is preserved, a sped-up voice sounds natural rather than high or chipmunk-like.

What format is the result?

The result is saved as an MP3, which plays on any device and in any app.

Does it work without internet?

After the page has loaded once, the speed change runs offline in your browser. You only need a connection to open the page the first time.

Change Audio Speed - Slow Down or Speed Up

Slow audio down or speed it up while keeping the pitch natural. Free, private, and right in your browser.

Drop an audio file here or click to upload

MP3, WAV, AAC, FLAC, M4A, OGG

Up to 500MB on desktop, 100MB on mobile

Fast 100% private Free

How to change audio speed

Add your audio

Drop in or pick the file you want to slow down or speed up. It stays on your device.

Pick a speed

Choose from 0.25x up to 4x. Below 1x slows it down, above 1x speeds it up.

Download

Save your new audio at the speed you chose.

Why change audio speed?

Speeding audio up turns a long lecture, audiobook or podcast into a faster listen. Slowing it down helps you transcribe an interview, learn a song by ear, or follow a fast talker word by word.

Sondra changes the tempo while keeping the pitch natural, so a sped-up voice does not sound squeaky and slowed audio does not drop into a low drone. The result sounds clear at any speed from 0.25x to 4x.

It works with MP3, WAV, AAC, FLAC, M4A and OGG, adds no watermark, and runs entirely in your browser. Open the page, drop in your file, choose a speed, and download.

What you can do with a speed change

Changing the playback speed is useful in a lot of situations. Here are the most common ones.

Speed up podcasts

Listen to a long episode or audiobook faster without the voice sounding odd.

Slow down to transcribe

Slow an interview or lecture so you can type along without rewinding.

Learn music by ear

Slow a song or solo down to hear and copy every note.

Practice a language

Slow down native speech to catch each word, then speed it back up.

Change audio speed for any use

A speed-changed MP3 plays everywhere. A few notes for the most common uses.

Podcasts and audiobooks

Speed up long recordings to get through them faster.

Music practice

Slow a track down to learn it, then bring it back to full speed.

Phone and messaging

The new file plays in any music or messaging app, with no extra app needed.

Voice notes

Speed up a long voice memo, or slow one down to hear it clearly.

Private by design

Most online speed changers upload your file to a server before processing it. Sondra does not. All the work happens inside your browser on your own device, so your audio is never sent anywhere and nobody else can hear it.

That also means there is no waiting for a long upload, no account to create, and no limit on how many files you change. Close the tab and nothing is left behind.