AVI to MP4
Convert AVI to MP4 for free. AVI is an old container with no browser hardware decoding, so this page transcodes in software — it works, but takes roughly 1 to 3 minutes per minute of video. Everything stays local; nothing is uploaded.
Result right hereDrop a video here, or click to choose
MP4 · MOV · MKV · WebM · audio · images · subtitles · ZIP
AVI dates from the nineties and now turns up mainly in old archives and some surveillance equipment. Phones, tablets and most current players will not touch it.
Stated plainly: browsers provide no hardware decoding for AVI, so this page falls back to software transcoding. It works, but it is much slower — roughly 1 to 3 minutes per minute of video depending on your machine. Other formats (MOV, MKV, WebM) use hardware and finish in seconds to a minute.
The first use downloads a decoding component of about 25 MB. It is downloaded only on this page; every other tool is unaffected. The MP4 you get is standard H.264 and plays anywhere.
FAQ
Why is AVI so much slower than everything else?
Because the hardware decoding chip in your device does not recognise the format, leaving software to compute frame by frame. That is a browser limitation, not laziness on our part — every purely web-based tool has it.
Can it handle large AVI files?
Yes, but slowly. Anything over a gigabyte is better done on a computer; a phone may run out of memory partway.
Will the quality drop?
The codecs inside old AVI files are limited to begin with, so converting to H.264 rarely looks worse and may even look slightly better at the same size, since the newer codec is more efficient.
What about WMV and FLV?
Not supported. If you have them, convert to MP4 with a desktop player such as VLC first, then come back.
Does that 25 MB component stay downloaded?
The browser caches it, so a return visit to this page does not download it again. Clearing browser data removes it. No other tool page ever loads it.