Convert Matroska (MKV) to AVI
Free online converter for Matroska (MKV) files. Legacy container with broad desktop support. Nothing to install, no watermark, and every file is deleted automatically.
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Upload a Matroska (MKV) file to convert it to AVI. Up to 3 files at once, 100 MB each.
Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.
About MKV and AVI
Matroska (MKV) .mkv
Matroska: an open container that will hold almost any combination of video, audio, subtitle and chapter tracks in one file.
Good for
- Unlimited tracks — multiple languages, subtitles, chapters
- Codec-agnostic, so it holds nearly anything
- Open, well documented, and resilient to damage
Trade-offs
- Browsers will not play it natively
- Many TVs and phones refuse it — the usual reason to convert
- Being a container, contents vary wildly file to file
video/x-matroska
AVI .avi
A Microsoft container from 1992. Still readable everywhere, but it predates modern streaming, subtitles and variable bitrate audio.
Good for
- Opens in very old software
- Simple, well-understood structure
Trade-offs
- Much larger than MP4 for the same quality
- No native subtitle support
- Poor handling of variable bitrate audio and modern codecs
video/x-msvideo
MKV and AVI side by side
| MKV | AVI | |
|---|---|---|
| Compression | Container — any codec | Container — usually older codecs |
| Transparency | Depends on codec | No |
| Typically used for | Archival video, multi-language releases | Legacy video files |
What changes when you convert MKV to AVI
MKV and AVI are unrelated containers
MKV is built on Matroska, an open container that accepts almost any codec. AVI is RIFF, Microsoft's chunk format from 1992. A container is a box, not a compression method: what decides how a video looks and how large it is, is the codec stored inside, and these two boxes accept different ones.
This is a re-encode, not a repackage
Some tools can move a stream into a different container untouched when the codecs happen to line up. We do not — every job here is decoded and encoded again, so the conversion takes time in proportion to the length of the file and costs a small amount of quality even where a repackage would have been possible. In exchange the output is predictable: it plays everywhere, rather than inheriting whatever the source happened to contain.
What your AVI will contain
The output is MPEG-4 Part 2 video with MP3 audio — the codecs AVI was built around, both roughly a generation behind what an MP4 would give you. The video is encoded at a constant quality target rather than a fixed bitrate, so the size of the result follows the complexity of the footage rather than being decided in advance.
AVI costs you size and quality
MPEG-4 Part 2 is roughly a generation behind H.264, so an AVI will usually be larger than an MP4 of the same clip at the same quality — not smaller. AVI also has no proper support for chapters, subtitles or modern metadata. Convert to it when a piece of old software or hardware will read nothing else, not for quality, size or convenience.