Compress Audio Files
Pick an MP3, M4A, WAV or other audio file and choose one of four quality levels. Our server makes a smaller copy and shows the size before and after, and levels that wouldn't shrink your file are grayed out.
Drop an audio file to compress
Drag file here or pick from your device
MP3, WAV, FLAC, M4A, AAC, OGG, OPUS, AIFF, AIF, WMA · up to 200 MB
How to
How to compress an audio file
You need the audio file on your computer or phone. The page reads it before anything is sent, so it can tell you which quality levels would actually make it smaller.
- 1
Pick the audio file
Drop the file on the box or click Browse file. The panel opens with the file's name and size, and a moment later the page's guess of how much space each second of sound takes, read on your device.
- 2
Choose a quality and a format
Click Basic, Good, High or Best quality; a grayed-out card marked "Source already at or below this quality" can't be picked. Then pick the kind of file you want back under Output format, which starts on MP3.
- 3
Compress and download
When you click Compress audio, the button reads Compressing... while the file uploads and our server makes the smaller copy, which took 3 to 12 seconds for each of our test files. A blue box then shows the size before and after, how much smaller it got and a Download button.
Guide
How small each quality level makes your audio
Each quality level gives the new file a fixed amount of space per minute of sound, so its size comes from the length of the recording and the level you pick, whatever the file weighed before. Basic makes about half a megabyte a minute, Good about 0.9 MB, High about 1.4 MB and Best about 1.8 MB.
That is why the same level can do a lot for one file and very little for another: our 25 second WAV of an orchestra went from 4.2 MB to 392 KB at Good, 91% smaller, while a speech MP3 that was already compressed only halved at Basic.
Why some levels are grayed out
When you pick a file, the page divides its size by its length to see how much space it already uses per second, then turns off every level that wouldn't shrink it. Our test MP3, a LibriVox reading, already sat at the Good level, so only Basic stayed open. Good is the starting choice, which means a yellow note shows straight away and Compress audio stays off until you click Basic.
When all four are grayed out
A short voice note can already be smaller than Basic would make it, and with our 60 second, 370 KB test memo every card was gray and the button never turned on. The yellow note still says to pick a lower quality, but there isn't one, so the file is about as small as this page can make it. To get it smaller, cut out the parts you don't need with Audio Cutter.
Sending audio by email or chat
Gmail won't attach a file over 25 MB, which holds about 54 minutes at Basic or 27 at Good. Basic is meant for speech, like a lecture, a voice memo or a podcast, and Good or High suits music. Our speech file kept its pauses in the same places and its loudness within half a decibel after Basic, but we only measured the sound, so play the result once before you send it.
Which format to save
MP3 opens on nearly every phone, car and computer, so it's the safe pick when you don't know what the other person uses. M4A is the format iPhones and Apple Music use, and the menu has to be switched to it before you compress. AAC, OGG and Opus are there for apps that ask for them, but you can't save WAV or FLAC here, since this page only saves the compressed formats on its menu. If a WAV just needs to become an MP3, WAV to MP3 does that in one step, and M4A to MP3 changes an M4A without asking about size.
What happens to your file
The size check runs in your browser, and nothing is sent until you click Compress audio, when the whole file goes to our server, which makes the smaller copy and deletes your upload as soon as it's done. The smaller copy is removed in a nightly cleanup, and so is the upload if the job fails. There's no progress bar for the upload, so a large file on a slow connection can sit on Compressing... for a while. Stereo stays stereo, and album art isn't copied into the new file.
Large files and long recordings
The box says up to 200 MB, but the network service in front of our server turns away uploads over about 100 MB, which is about 10 minutes of CD-quality WAV or an hour and a half of a typical MP3. We only tested files under 2 minutes, and the server gives up on a job after 10 minutes of work. If your browser can't read a file, as Chrome couldn't with an M4A in Apple's highest-quality format in our test, the page can't check its size, so all four levels stay open and it's up to you to pick one smaller than the original.
Last updated: 22 October 2026 · ChangeMyFile
Tested: 22 October 2026, local page in headless Chrome against the live server, one job at a time. Sources: Mozart's Figaro overture played by the Musopen Symphony (public domain, Wikimedia Commons) and the LibriVox public domain reading of the Gettysburg Address. 25 s WAV (4,410,216 bytes, 16-bit PCM, 44.1 kHz stereo) at Good to MP3: 3.2 s from click to result, page showed 4.2 MB to 392 KB, 90.9% smaller; file 401,434 bytes, MP3 128 kbps, 44.1 kHz stereo, 25.00 s. 100 s M4A (AAC 256 kbps, 3,210,767 bytes) at Good to M4A: 11.7 s, 3.1 MB to 1.5 MB, 49.5% smaller; 1,622,561 bytes, AAC 128 kbps stereo, 100.01 s, same loudness and peak as the input. 110 s MP3 (128 kbps, 1,761,025 bytes) at Basic to MP3: 4.9 s, 1.7 MB to 860 KB, 50.0% smaller; 881,010 bytes, 64 kbps stereo, 109.99 s, pauses in the same place, mean level 0.5 dB lower, no clipping. On the 128 kbps MP3 the page grayed out Good, High and Best. A 60 s, 48 kbps mono M4A (page estimate ~51 kbps) grayed out all four levels. An Apple Lossless M4A could not be read by Chrome, so no estimate showed and all four stayed open.
FAQ
Compress audio questions
At a glance
- Where it runs
- On our server; the size check in your browser
- Files you can add
- MP3, WAV, FLAC, M4A, AAC, OGG, Opus, AIFF, WMA
- Saves as
- MP3, M4A, AAC, OGG or Opus
- Size limit
- About 100 MB, one file at a time
- Download link
- Works for 30 minutes
- Files deleted
- Your upload once the job is done, the rest in a nightly cleanup
- Account
- Not needed
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