AVI to MP4 Converter

Convert AVI video to MP4 so modern devices will play it. Runs on your own device — the file is never uploaded.

  • 100% private
  • No sign-up
  • No watermark
  • Unlimited files
Drop a AVI file hereor tap to browse · one file at a time · nothing is uploaded

    On the default setting this usually finishes in seconds, because the picture and sound are copied across unchanged rather than re-encoded. Everything runs on your own device — the file is never uploaded.

    AVI is old, and that is the whole problem

    AVI dates from 1992. It predates almost everything about how video is handled now: it has no proper support for modern codecs, handles variable frame rates badly, and carries no standard way to store the metadata that current players expect.

    Files in AVI are usually old camcorder footage, ripped discs, or video from software long since retired. They tend to contain codecs like DivX, Xvid, MPEG-4 Part 2 or motion JPEG — formats that were current twenty years ago and that most phones and televisions no longer recognise.

    Fast or slow depends on what is inside

    Some AVI files hold MPEG-4 Part 2 video, which an MP4 container can carry, so the conversion is a quick repackaging. Others hold codecs that cannot go into an MP4 at all, and every frame has to be re-encoded, which takes minutes.

    You cannot tell from the file name which you have. This tool reads the codecs and picks the right approach, then tells you which one it used once the file is ready.

    Expect a much smaller file

    This is the one conversion in the video category where the output is usually far smaller than the input. Old codecs are dramatically less efficient than H.264, so re-encoding an AVI often halves the size or better while looking essentially the same.

    It is a rare case where converting genuinely improves the file rather than trading one property for another.

    Frequently asked questions

    Are my files uploaded to a server?

    No. The conversion runs inside your browser using your device's own processor. Your files are never transmitted anywhere, which is why the tool works even if you disconnect from the internet after the page loads.

    Why is my MP4 so much smaller than the AVI?

    AVI files usually contain codecs from the early 2000s that are far less efficient than H.264. Re-encoding to a modern codec commonly halves the size with no visible difference.

    Will the audio still be in sync?

    It should be. AVI handles variable frame rates poorly, which is the usual cause of drifting sound in old files — re-encoding normalises the timing and often fixes sync problems rather than creating them.

    My AVI will not play at all. Can this still convert it?

    Usually yes. The converter includes decoders for old codecs your media player probably lacks, so a file that will not open on your computer can often still be converted.

    Is there a file limit or a paywall?

    There is no account, no watermark, and no upload cap. Because your device does the work, the only practical limit is your available memory. The site is funded by ads, not subscriptions.

    Further reading

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