Drop your MP4 file. We'll convert it to AVI right here in your browser, your file never leaves your device.
MP4
to
AVI
Select your file here to get started
or drop your file here.
Accepts .mp4, .m4v
nothing uploaded no file size cap no signup
How it works
Three steps. No upload, no signup.
1
Drop your file
Click the dropzone above or drag a MP4 from your desktop. Files of any size, there's no upload, so there's no upload limit.
2
Convert in your browser
The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.
3
Download
Get your AVI the moment the conversion finishes. Convert another, or close the tab.
Files stay on your device
Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.
No file size limit
Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.
Free, no signup, no ads on conversions
No account required. No watermark on the output. No queue. Drop a file, get a converted file.
Formats involved
About MP4 and AVI
MP4, MPEG-4 Part 14
MP4 is the dominant video container on the web, H.264 video plus AAC audio, in a structure designed for streaming. Every browser, mobile device, smart TV, and editing tool reads MP4. The format is technically a container (not a codec), so two MP4 files can have very different internal codecs, but the H.264+AAC default is what enables universal playback.
How to open
Every video player on the planet, VLC, QuickTime, Windows Media Player, browsers (HTML5 video), iOS, Android, smart TVs, game consoles. Universal.
AVI is Microsoft's video container from 1992, a workhorse for older Windows software, security camera systems, and legacy editing workflows. The format itself is durable but inefficient compared to MP4: same content takes 2-3× more disk space. Modern video software reads AVI but rarely writes it; converting old AVI archives to MP4 is the standard modernization path.
How to open
VLC, every video player, every video editor. Smart TVs and mobile devices may struggle, convert to MP4 if you want to play AVI on a TV.
Last verified May 2026 from each competitor's pricing and FAQ pages. Limits and pricing change frequently.
FAQ
Common questions
Is this MP4 → AVI converter really free?
Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.
Where does my file go when I convert it?
Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.
What's the maximum file size?
Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.
Why convert MP4 to AVI?
Web video, mobile video recording, video sharing. Legacy video, security camera footage, older Windows workflows. The most common reason to convert is compatibility, AVI works in places where MP4 doesn't, or vice versa.
How do I open a MP4 file in the first place?
Every video player on the planet, VLC, QuickTime, Windows Media Player, browsers (HTML5 video), iOS, Android, smart TVs, game consoles. Universal.
Does this work offline?
Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.
Can I convert multiple files at once?
Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.