Convert AVI files to MP4 so old camcorder footage, downloaded clips and archived video open on phones, in editors and on the web. Xvid and DivX files are handled as well as newer H.264 ones. Everything happens in your browser, so nothing is uploaded and no account is needed.
or click to select a file
🔒 Your files never leave your device - 100% private & secure
Drag a .avi file onto the upload area or click Select Video. The file stays on your device.
AVI needs a decoder browsers do not include, so about 9 MB is downloaded the first time you convert one. It is cached afterwards.
MP4 is selected automatically. Click Convert, then download the MP4 when it finishes.
AVI is one of the oldest video containers still in circulation. Microsoft introduced it in 1992, and for a decade it was what Windows wrote by default, which is why it turns up in old camcorder transfers, ripped discs, downloaded clips and anything archived from a PC of that era.
Its problem today is not the picture but the packaging. No mainstream browser plays AVI, most phones refuse it, and many editors and upload forms reject the extension outright. The video inside is usually still perfectly watchable; it is simply wrapped in a container nothing modern wants to open.
MP4 is the format everything accepts. Converting puts the same footage into a container that plays on any phone, uploads to any platform and opens in any editor, and the resulting file is normally smaller because MP4 carries far less overhead than AVI's index-and-chunk structure.
How long it takes depends on what is inside. A newer AVI holding H.264 video can be repackaged almost instantly, with the picture copied across untouched. An older one holding Xvid or DivX has to be decoded and re-encoded, because no browser can read those, and that takes roughly as long as the video is. Either way it runs on your machine, with no upload and no watermark.
Browsers can read MP4, MOV, MKV and WebM on their own, but not AVI. Converting one needs a decoder that is not built in, so about 9 MB is fetched the first time and cached for later. It is code, not your video - the file itself never leaves your device.
It depends on the video codec inside, which the extension does not tell you. An AVI holding H.264 is simply repackaged, which takes seconds whatever its length. An AVI holding Xvid or DivX, which is what most files from the 2000s contain, has to be fully decoded and re-encoded, and that takes roughly as long as the video plays.
For an AVI already holding H.264, no - the video is copied across rather than re-encoded. For Xvid and DivX files the video has to be re-encoded, so there is some loss, though at the default settings it is not something you would notice next to the original.
No. The conversion runs in your browser using WebAssembly, so the video never leaves your device. That is also why there is no file size limit beyond your own available memory, and no queue.
There is no hard limit, but AVI files that need re-encoding are the most demanding thing this site does. A few hundred megabytes is comfortable on a desktop computer; a multi-gigabyte file on a phone may run out of memory.