avi → mp4
AVI to MP4, for footage that predates streaming
AVI is a format from the 1990s and most modern devices have quietly stopped supporting it. This brings the same video into a container everything still reads.
Files are processed on your device · nothing is uploaded, stored or logged
How it works
Pick your file. The browser reads it straight from disk. There is no upload progress bar, because there is no upload.
The encoder loads once. A WebAssembly build of FFmpeg, around 30 MB, downloads the first time you use the site and stays cached afterwards.
Your processor does the work. Everything happens in this tab, at roughly half of real time on a modern laptop.
Save the result. The finished file is assembled in memory and handed to your downloads folder.
Why AVI files stopped working
AVI was designed by Microsoft in 1992, long before streaming, phones or hardware decoding. It has no proper support for modern codecs, variable frame rates or the metadata players expect, so support for it has been quietly dropped almost everywhere.
The video inside is usually still fine. Old camcorder tapes, screen captures from early software and archived home footage all sit in AVI files that play nowhere except VLC.
Converting to MP4 does not improve the picture — nothing can recover detail that was never recorded — but it makes the footage usable again on a phone, a TV or a video platform.
Expect a full re-encode
Unlike MOV or MKV, an AVI almost never holds H.264, so its contents cannot simply be repackaged. Expect the conversion to take real time proportional to the clip length. Old footage is usually low resolution, which makes this faster than it sounds.
Old AVI footage sometimes has an irregular frame rate that upsets editors. Fix it with change frame rate.
Common questions
Will it look better after converting?
No. Conversion changes the packaging, not the source quality. Upscaling old footage is a separate problem this tool does not try to solve.
My AVI has no sound after converting.
Some old AVI files use audio codecs that were never widely licensed. If that happens, the video still converts but the audio track cannot be read.
Is DivX or Xvid supported?
Yes, both decode correctly. They were the two most common codecs inside AVI files during the format's peak.
Do my files get uploaded?
No. Everything runs locally in this tab.