AVI to MKV converter

Convert AVI video to MKV in your browser. When the codec fits, only the container changes, so it takes seconds and the quality stays the same.

    Drop AVI files here or choose files.

    • 500MB per file. Up to 10 minutes when only the container changes, 3 minutes when re-encoding. Up to 5 files at a time
    • The first time you use it, the browser downloads the video engine (about 31MB)

    Auto skips re-encoding when the source can go into the new format as is, which is fast and keeps the quality intact. Otherwise it re-encodes at normal quality. Light reduces the file size at some cost in picture quality.

    For vertical video this refers to the shorter side. Choosing a size smaller than the original forces a slower re-encode. The tool never upscales.

    Files never leave this device. Privacy policy

    Result

    Upload a AVI video and click Convert. The MKV file will appear here.

    What to do next

    MKV to AVI converter

    Convert a MKV video back to AVI.

    Compress an AVI file

    Shrink the video to fit iMessage, Gmail or Discord upload limits.

    Trim a video

    If a video is too long to convert, cut out the part you need first. Quality stays the same.

    How it works

    Choose a AVI video and click Convert to save it as MKV. MKV is a container that can hold almost any video and audio codec as is, so most conversions finish in seconds with no re-encoding. It plays well in VLC and other desktop players.

    With quality set to Auto, the tool first checks the codec inside the video. If MKV can hold it as is, it swaps only the container without re-encoding. That takes a few seconds and the quality is unchanged. If the codec does not fit, the tool re-encodes and tells you below the result which method it used. Several files convert one after another.

    Things to know

    MKV cannot store rotation metadata, so vertical videos are re-encoded (up to 3 minutes). The iPhone Photos app and some TVs cannot open MKV.

    Re-encoding processes every frame on your device, so it is slow. That is why the limit is 10 minutes when only the container changes and 3 minutes when re-encoding. 4K video is reduced to 1080p when it has to be re-encoded.

    Frequently asked questions

    Which AVI files work?

    Old camcorder, Xvid and DivX AVI files use dated video codecs, so they are re-encoded to H.264 (up to 3 minutes). The rare AVI that already contains H.264 is copied as is, which is fast. If the file is damaged or uses an unusual codec, the tool tells you why it failed.

    What is the advantage of converting to MKV?

    The video and audio inside are left untouched. Only the container changes, so it is fast and the quality is identical. The iPhone Photos app and some TVs cannot open MKV, though, so for watching on a phone, MP4 is better.

    Why does it take so long? Does it work on a phone?

    The video is processed on your device, not on a server. When only the container changes, it takes a few seconds. When the video has to be re-encoded, it can take several times the length of the video depending on your hardware. It works on a phone but much more slowly, and it stops if the screen turns off or you switch apps. For long videos, use Chrome or Edge on a computer.

    Are my files uploaded to a server?

    No. The conversion runs entirely in this browser, and the file never leaves your device. The only download is the conversion engine, once. The result disappears when you close the page, so use the save button to keep it.

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