anytools
Video · 59 tools · nothing uploads

AVI to MP4

Convert an old AVI (usually MPEG-4 Part 2/DivX/Xvid) to MP4. No browser decodes that codec through WebCodecs, so this runs through a 32MB ffmpeg engine you download once, after you consent, from this site.

Input

Options

AVI to MP4 turns an old AVI file, most often built around MPEG-4 Part 2, DivX or Xvid, into a real MP4. WebCodecs has no decoder for that codec family in any browser, so the run goes through a 32MB ffmpeg engine, downloaded once after you tick a consent box. Leaving that box unticked gets the file refused outright.

Questions

Why does this need a 32MB download?

Because AVI usually carries MPEG-4 Part 2, DivX or Xvid, codecs no browser decodes through WebCodecs at all. mediabunny always refuses these, so this page goes straight to a 32MB ffmpeg.wasm engine rather than trying the browser path first and failing.

Do I have to agree to anything?

Yes. The fallback option defaults to off, so a first-time visitor sees a consent dialog and has to click it before the 32MB engine downloads. Nothing downloads on its own from opening the page alone.

Which engine handles this, and where can it run?

ffmpeg.wasm, downloaded once from this site after consent and never from a third-party CDN, does the decode and encode, since mediabunny cannot touch this codec family at all. This is browser only; the command line and MCP refuse it outright, since there is no consent step to grant on those surfaces.

What size should I expect?

A real re-encoded MP4 with a genuine mdat box. The fixture-tested output for a one-second, 64 by 64 test clip lands close to that duration and resolution, with the status text naming the ffmpeg fallback engine that ran.

What is the reverse page?

There is none. Nothing on this site writes AVI.

Related Video tools

n→nMOV to MP4Repackage a QuickTime MOV into MP4. Both are the same ISOBMFF box family carrying the same H.264/H.265 and AAC, so every packet is copied across with no decode and no re-encode.Runs on each file you dropn→nMKV to MP4Repackage a Matroska MKV into MP4 with no decode and no re-encode. A subtitle or attachment track MP4 has no room for is dropped and named, the video and audio packets are copied across untouched.Runs on each file you dropn→nTS to MP4Repackage an MPEG transport stream (.ts) into MP4. TS repeats its stream tables throughout the file for channel-hopping and has no seek index; MP4 gets one, so the same packets seek instantly once copied across.Runs on each file you dropn→n3GP to MP4Repackage an old 3GP mobile video into MP4. 3GP is already an ISOBMFF variant carrying H.264/AAC or the older H.263/AMR, so a modern player that refuses the 3GP extension plays the identical packets once they sit in an MP4 box.Runs on each file you dropn→nMP4 to WebMTranscode an MP4 to WebM. H.264/AAC and VP8-VP9/Opus are unrelated codec families, so every frame is decoded and re-encoded rather than copied, in the browser only, through WebCodecs.Runs on each file you dropn→nWebM to MP4Transcode a WebM to MP4. VP8/VP9/AV1 and Opus/Vorbis are not MP4-native codecs, so this decodes and re-encodes every frame through WebCodecs, in the browser only, rather than repackaging the bytes.Runs on each file you dropn→nMP4 to GIFTurn an MP4 clip into an animated GIF. WebCodecs decodes the frames and this tool builds the GIF89a bytes itself: one shared 256-colour palette across every sampled frame, no dithering. Browser only.Runs on each file you dropn→nMOV to GIFTurn a QuickTime MOV screen recording or clip into an animated GIF. WebCodecs decodes the frames and this tool builds the GIF89a bytes itself, one shared palette across every sampled frame. Browser only.Runs on each file you drop