Super Boring Tools

Search tools

Find a tool by name or what it does.

Change Audio Speed

Speed up or slow down an MP3, WAV, M4A, or OGG file with the pitch preserved, right in your browser.

Audio
Drop an audio file here or click to browse
or paste from clipboard (Ctrl+V) · MP3, WAV, M4A, OGG
Files stay in your browser. Nothing is uploaded.
Speed

How to change the speed of an audio file online

  1. Add your audio file

    Drop in the MP3, WAV, M4A, or OGG file you want to speed up or slow down, or click to browse.

  2. Choose a speed

    Pick 0.5x or 0.75x to slow the audio down, or 1.25x, 1.5x, 2x, or 3x to speed it up. The preview player follows the selected speed.

  3. Change speed

    Click Change speed. The audio is re-timed with the pitch preserved, so voices and music keep their natural tone.

  4. Download

    The result card shows the original and new length. Play the rendered file to check it, then click Download to save it.

Why use this tool

Six speed presets

0.5x and 0.75x slow a recording down for practice and transcription; 1.25x, 1.5x, 2x, and 3x shorten it for faster listening.

Pitch stays natural

The tempo is changed without shifting the pitch, so a voice at 2x does not turn squeaky and music at 0.5x does not drop into a growl.

Live preview

A built-in player plays your original file at the selected speed, so you can judge the pace before rendering the download.

Before-and-after durations

The result card shows the original length next to the new one, so you can confirm the change before saving.

Keeps the input format

An MP3 is saved as an MP3, and the same goes for WAV, M4A, and OGG. Anything else is saved as MP3 so it plays everywhere.

Nothing is uploaded

The whole speed change runs in your browser, so the recording never leaves your device.

About this tool

This tool changes the playback speed of an audio file and saves a new copy at the chosen tempo. Everything runs in your browser: the file is decoded locally, re-timed, and re-encoded without being uploaded anywhere. Six presets cover 0.5x to 3x, and the pitch is preserved at every one of them. That last part matters, because naive speed changes shift pitch along with tempo, which is why sped-up voices are known for sounding like chipmunks. Here a lecturer at 2x sounds like the same person talking quickly, and a track slowed to 0.5x stays in its original key.

Typical uses are speeding up lectures and podcast episodes for review, slowing a solo or riff down to learn it phrase by phrase, and running interviews at 0.75x so transcription keeps pace with playback. The built-in player previews the original at whichever speed is selected, which is enough to judge the pace; the download itself is rendered properly at that speed. Output stays in the input's family, so an MP3 comes back as an MP3, and the same goes for WAV, M4A, and OGG. Less common formats are saved as MP3.

Changing speed requires a re-encode, so a three-minute song takes seconds while a two-hour recording takes noticeably longer, and nothing leaves your device at any point. To re-time only a section, trim the audio first. For clips with a picture, the video speed changer does the same job for video, and the audio converter changes formats without touching the speed.

Frequently asked questions

Does speeding up or slowing down change the pitch?
No. The tool changes the tempo of the audio while keeping the pitch where it was. Without that, faster playback raises the pitch until voices sound like chipmunks, and slower playback drops them into a low drone. Here a podcast at 2x sounds like the same host talking quickly, and a song at 0.5x stays in its original key.
Which audio formats are supported?
MP3, WAV, M4A, and OGG files are accepted, and most other common audio files work too. The download keeps the input format: MP3 in, MP3 out, and the same for WAV, M4A, and OGG. Less common inputs are saved as MP3, which plays everywhere.
Is the preview the same as what I download?
The preview plays your original file through the browser's built-in player at the selected speed, so you can judge the pace before committing. The download is a separate, properly rendered file at that speed. A few formats cannot be previewed in every browser; the speed change and download still work for those files.
Does changing the speed reduce audio quality?
The file is re-encoded, so lossy formats like MP3, M4A, and OGG lose a little fidelity in the process, though for spoken word it is hard to hear. WAV output stays uncompressed. Re-timing itself can add faint artifacts at the extremes, most noticeably in music at 3x.
Is my audio uploaded to a server?
No. The whole speed change runs locally in your browser. Your file is never uploaded, stored, or logged anywhere. The first time you use the tool it downloads the audio engine once, then keeps it ready for the rest of your session.
How long does it take, and is there a size limit?
Processing time grows with the length of the recording: a three-minute song takes seconds, while a two-hour lecture can take a few minutes, and desktops are quicker than phones. There is no fixed file-size cap, but very large files depend on your device's memory, so it helps to cut the file down before changing its speed.

Related tools