Question 1

Will going from AAC to Opus make it sound better?

Accepted Answer

AAC and Opus both shrink the sound a little to keep files small, so saving from one to the other adds a tiny bit more loss. Pick High or Maximum quality to keep that loss to a minimum.

Question 2

Why would I want to change AAC to Opus?

Accepted Answer

Different phones, speakers, and apps prefer different formats. Saving as Opus can make a song play where AAC won't. The best small-size sound. Used for podcasts, voice chat, and the web.

Question 3

Is it really free?

Accepted Answer

Yes. No accounts, no waiting, no watermarks, no file-size limits. The site shows ads to pay the bills — the converter itself is fully unlocked for everyone.

Question 4

Where do my files go?

Accepted Answer

Nowhere. Your songs stay on your own phone or computer the whole time. Nothing is sent to any server. You can even use the site offline once it has loaded once.

Question 5

How big can a file be?

Accepted Answer

Up to 500 MB per file. That is enough for several hours of music. If you have something much bigger, like a long audiobook, a desktop program will handle it more easily.

Question 6

Why is the first conversion slow?

Accepted Answer

The first time you use the site, your browser downloads the small piece of software that does the work — about 30 MB. After that, every conversion starts straight away.

Convert AAC to Opus

Drop AAC files here

Why convert AAC to Opus?

Frequently asked questions