AVI Converter
FileFlip converts AVI files into 30 other formats entirely inside your browser, using WebCodecs and FFmpeg compiled to WebAssembly. The AVI file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert an AVI file?#
- Drop your AVI file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
Is it safe to convert AVI files online?#
Yes, because nothing is uploaded. FileFlip converts AVI files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What happens to a AVI file#
FileFlip converts AVI into 30 formats with WebCodecs and FFmpeg, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | Video Files |
|---|---|
| File extension | .avi |
| FileFlip support | Read and written |
| Conversions available | 30 |
| Engines | WebCodecs and FFmpeg |
| Downloaded to your browser | 30.8 MB on the first conversion, then cached |
What is an AVI file?#
An AVI file interleaves video and audio in chunks of Microsoft's RIFF structure, the container Windows has used for video since 1992 and the one most video from the DivX and Xvid years is stored in.
Keep a file as AVI when it is going into software old enough to predate MP4, which is the one situation where the format's age helps.
Convert AVI to MP4 to get the video playing on phones, browsers and TVs, and to shrink it, since what is inside an AVI is usually a codec generation or two behind.
The AVI file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
AVI questions people ask#
Why won't my AVI file play?
An AVI that will not play is usually encoded with a codec the machine does not have. AVI identifies its video by a four character code and leaves the decoder to the operating system, which is why Windows users spent years installing codec packs. Old DivX, Xvid, Indeo and Cinepak files all hit this. VLC ships its own decoders and plays most of them, and converting to MP4 removes the problem permanently.
Is AVI a codec or a container?
AVI is a container, and an unusually open-ended one. Any codec that registers a four character code can go inside, so AVI files from different eras hold wildly different things: MJPEG from a camera, Cinepak from a CD-ROM, DivX or Xvid from a download. That is why one AVI plays instantly and the next one shows a black screen on the same computer.
Does converting AVI to MP4 lose quality?
Converting AVI to MP4 nearly always re-encodes the video, so some quality is lost. AVI predates H.264 and H.265, which is what MP4 players expect, so the old DivX or Xvid stream cannot simply be rewrapped the way an MKV can. Encoding at a generous bitrate keeps the loss invisible in practice, and the result usually still ends up smaller than the AVI.
Why is my AVI file so large?
AVI files are big because of what is inside them rather than the container itself. The codecs of the era, MJPEG and DivX among them, need several times the bitrate H.265 does for the same picture, and MJPEG stores every frame as a separate JPEG with no saving between frames at all. Re-encoding the same footage to H.264 or H.265 in an MP4 commonly cuts the file to a fraction of its size.
Can AVI files have subtitles?
AVI has no subtitle track, so subtitles for an AVI live in a separate SRT or SUB file sitting next to it with a matching filename, and the player pairs them up. Move the video without the sidecar file and the subtitles are gone. Converting to MKV or MP4 lets the subtitles be embedded in the video file itself, which is the usual reason people move AVIs into a newer container.