Question 1

How much smaller will my MP3 get?

Accepted Answer

An MP3's size depends on its bitrate and length. At 128 kbps it uses about 1 MB per minute; at 96 kbps, about 0.7 MB per minute. Going from 320 to 96 kbps cuts the size by roughly 70%.

Question 2

Which bitrate should I use?

Accepted Answer

96 kbps is fine for speech, podcasts and voice memos. For music, 128 kbps is the usual compromise, and 192 kbps sounds close to the original for most listeners.

Question 3

Why did my file get bigger?

Accepted Answer

If the original was already encoded at a lower bitrate than the one you picked, saving it again at a higher bitrate makes the file larger without improving the sound. Check the original bitrate with the Audio File Info tool and pick a lower one.

Question 4

Can I compress a WAV file?

Accepted Answer

Yes. A CD-quality stereo WAV uses about 10 MB per minute, so saving it as a 128 kbps MP3 makes it around 10 times smaller.

Question 5

Is there a smaller format than MP3?

Accepted Answer

Opus, saved as OGG (Opus) or Opus, sounds better than MP3 at the same bitrate, so it loses less quality at a small size. It plays in modern browsers and on Android, but some older players and car stereos only handle MP3.

Question 6

Can I compress several files at once?

Accepted Answer

Yes. Drop several files and each one is compressed with the same settings. The first file downloads free; the others, and a ZIP of all of them, need Pro.

Question 7

Are my files uploaded to compress them?

Accepted Answer

No. Compression runs in your browser and your files never leave your device. Free downloads go up to 100 MB per file.

MP3 Compressor

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