Convert Matroska to AAC
We turn Matroska into AAC right in your browser — the file never goes to a server.
What you will lose
- Compression becomes lossy: the original quality cannot be restored
How they differ
| Matroska | AAC | |
|---|---|---|
| Lossless | yes | no |
| Lossy | yes | yes |
| Multichannel | yes | yes |
| Tags | yes | yes |
| Released | 2002 | 1997 |
| Author | CoreCodec | MPEG |
Matroska
Good at
- Takes anything inside: any codec, a dozen tracks, subtitle fonts
- The one common container people fill with lossless audio
- Tracks and subtitles can be swapped without touching the picture
Awkward about
- TVs and phones often refuse to open it
- No browser plays it directly
- Files run larger: what goes inside is usually less compressed
Use it when
- A home archive where everything should be kept as it was
- Several audio languages and subtitle tracks in one file
- The file is watched on a computer, not on household hardware
AAC
Good at
- Noticeably better than MP3 at the same size
- The native format for Apple gear and most phones
- Handles multichannel audio and tags
Awkward about
- Older devices and car stereos may refuse it
- Lossy — the original cannot be recovered from it
- Encumbered by patents, unlike Opus
Use it when
- Listening on a phone without wasting quality
- A voice memo, or a track pulled out of a video
- You want a balance between size and sound
Common questions
- Does the file get uploaded to a server?
- Yes, this pair needs the server: browsers cannot encode that format. The file and the result are deleted within a couple of hours and never shared.
- Will surround sound survive?
- Yes, AAC carries more than two channels — 5.1 stays 5.1.
- Can I get the original quality back afterwards?
- No. AAC is lossy, and the discarded detail cannot be recovered. Keep the original if you may still need it.
- How many files, and how large?
- Up to 5 files at a time, 500 MB each. No sign-up, no watermarks.