How do I convert MP4 to AVI?

Upload your MP4 file using the box above, confirm AVI as the output format, then select Convert. The converted file is ready to download as soon as processing finishes — usually in a few seconds.

Is converting MP4 to AVI free?

Yes, and there is nothing to sign up for. Every conversion route is free on every plan — paying raises limits such as file size and how many conversions you get, and removes advertising. It never unlocks a format, adds a watermark or degrades the output.

Will the quality change when converting to AVI?

AVI uses lossy compression, so some data is discarded to keep the file small. The default quality setting is tuned to be visually or audibly transparent for most material, and you can raise it in the conversion settings.

What happens to my file afterwards?

The uploaded file is deleted as soon as the conversion completes, and the converted file is removed automatically once its retention window ends. Download links are signed and expire within minutes.

mp4avi

Convert MP4 to AVI

Free online converter for MP4 files. Legacy container with broad desktop support. Nothing to install, no watermark, and every file is deleted automatically.

Drag and drop your files

Upload a MP4 file to convert it to AVI. Up to 3 files at once, 100 MB each.

Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.

About MP4 and AVI

MP4 .mp4

The universal video container, normally holding H.264 video and AAC audio. If a device plays video at all, it plays MP4.

Good for

Plays on effectively every device, browser and editor
Excellent compression at high quality
Streams well, and seeks quickly

Trade-offs

H.264 carries patent licensing obligations
Lossy — quality drops each time it is re-encoded
Less flexible than MKV for subtitles and multiple tracks

video/mp4

AVI .avi

A Microsoft container from 1992. Still readable everywhere, but it predates modern streaming, subtitles and variable bitrate audio.

Good for

Opens in very old software
Simple, well-understood structure

Trade-offs

Much larger than MP4 for the same quality
No native subtitle support
Poor handling of variable bitrate audio and modern codecs

video/x-msvideo

MP4 and AVI side by side

MP4 compared with AVI
	MP4	AVI
Compression	Lossy (usually H.264)	Container — usually older codecs
Transparency	No	No
Typically used for	Everything — the safe default for video	Legacy video files

What changes when you convert MP4 to AVI

MP4 and AVI are unrelated containers

MP4 is built on the ISO base media format, derived from QuickTime. AVI is RIFF, Microsoft's chunk format from 1992. A container is a box, not a compression method: what decides how a video looks and how large it is, is the codec stored inside, and these two boxes accept different ones.

This is a re-encode, not a repackage

Some tools can move a stream into a different container untouched when the codecs happen to line up. We do not — every job here is decoded and encoded again, so the conversion takes time in proportion to the length of the file and costs a small amount of quality even where a repackage would have been possible. In exchange the output is predictable: it plays everywhere, rather than inheriting whatever the source happened to contain.

What your AVI will contain

The output is MPEG-4 Part 2 video with MP3 audio — the codecs AVI was built around, both roughly a generation behind what an MP4 would give you. The video is encoded at a constant quality target rather than a fixed bitrate, so the size of the result follows the complexity of the footage rather than being decided in advance.

AVI costs you size and quality

MPEG-4 Part 2 is roughly a generation behind H.264, so an AVI will usually be larger than an MP4 of the same clip at the same quality — not smaller. AVI also has no proper support for chapters, subtitles or modern metadata. Convert to it when a piece of old software or hardware will read nothing else, not for quality, size or convenience.