What is this AVI to MKV converter?
A free, browser-based tool that converts a AVI video to MKV. Add a file, preview it inline, and download the result. All processing happens locally in your browser, so your video is never uploaded and there is no watermark.
Where these AVI files come from, and why MKV suits them
Most AVI files worth keeping date from the capture era: DV tape transfers that fill about 13GB per hour, 2000s camcorder clips, and early screen recorders that wrote MJPEG or Xvid. The footage still plays, but the container around it stopped evolving twenty years ago: no chapters, no proper subtitle tracks, awkward metadata.
MKV is the natural shelf for this material. It accepts practically every codec ever used inside an AVI, which is exactly what you want for preservation: the point is to modernize the wrapper, not to touch the picture.
A container swap with nothing re-encoded
Because MKV can hold whatever the AVI carries, this conversion is almost always a remux: the video and audio streams are copied into the new container untouched. That takes moments rather than minutes, and the output is bit-for-bit the same footage, which matters for files that have already survived two decades of disk migrations.
The best fit is clip-length material; around 200MB per file is the practical ceiling, so full-tape DV masters belong in a desktop workflow. Once in MKV, your archive also gains room for chapters, several audio tracks, and soft subtitles whenever you add them later.
How to use it
- Add a AVI file on the left (drag & drop or click) — it shows an inline preview.
- Pick a quality preset (used only when the video has to be re-encoded).
- Press “Convert & download” to get your MKV file. The first run downloads the ~30MB converter once.
Lossless remux vs re-encoding
AVI and MKV are containers — what matters is the video codec inside. When the codec already fits MKV, this tool just repackages it (a "remux"): instant and completely lossless. Only when the codec isn't compatible — most often anything involving WebM — does it re-encode the video locally, which takes longer and is where the quality preset applies.