How to compress an audio file
Drop your recordings into the box above, or click Choose files. MP3, M4A, WAV, OGG, FLAC and videos work.
Choose Recommended for speech, Light for music or Strong for the smallest file, or set a size limit such as 16 MB.
Click Compress audio. Each file comes out as an MP3.
Listen, and download the files one by one or as a ZIP.
Why compress audio?
Phones record in large formats, and a WAV or an hour-long lecture quickly runs into the limits of WhatsApp, e-mail and upload forms.
Speech needs far less than music: a mono MP3 at 64 kbps sounds just as clear for a voice and is a fraction of the size, so it sends and plays anywhere.
Which level should I choose?
Light keeps stereo at 128 kbps, close to the original for music. Recommended is 64 kbps mono, clear for voices at about half the size of a typical MP3.
Strong is 32 kbps mono for the smallest file: fine for lectures and meetings, noticeably duller for music. With a size limit, the best quality that fits the recording's length is chosen for you.
Is it safe?
Yes. Compress Audio runs entirely in your browser. Your files are read and converted by your own device using built-in browser technology, so they are never uploaded to a server and nobody else can see them.
You can check this yourself: open your browser's developer tools, switch to the Network tab and convert a file. No upload requests are made.
Your recordings are compressed in your browser and never uploaded.
Files stay in this tab's memory only until you remove them or close the page.
Frequently Asked Questions
How do I get a recording under WhatsApp's limit?
Choose the 16 MB size limit. Each file comes out under it at the best quality its length allows; a very long recording may turn mono.
Will my voice still sound clear?
Yes. Speech sounds clear at Recommended, and still understandable at Strong. Music is where lower levels are noticeable.
Why did my MP3 stay the same?
It was already small; compressing it again would have made it bigger or worse, so the original was kept.
Can I compress the sound of a video?
Yes. Drop the video in and you get its sound as a compressed MP3. To make the video itself smaller, use Compress video.
What if it can't get small enough?
Even at the lowest quality a very long recording may be over a small limit. Cut it into parts with the MP3 Cutter, or choose a larger limit.