Convert MP4 to AVI Online
AVI to MP4Convert MP4 video to AVI directly in your browser. Free, no signup, and your file is never uploaded.
Click to upload or drag a file here
Supported: MP4 · Processed entirely in your browser
Converted entirely in your browser using a WebAssembly build of FFmpeg — your file is never uploaded anywhere. Larger files take longer and use more memory.
MP4 to AVI converts a modern MP4 video into the older AVI format, occasionally still needed for compatibility with legacy editing software or playback devices that never moved on from it.
Why would anyone need AVI specifically today, when MP4 is so much more common?
Older editing software, some legacy playback devices and certain archival or broadcast systems were built around AVI and were never updated to handle newer containers natively — converting a modern MP4 down to AVI is sometimes the only way to make a current video file compatible with that older piece of software or hardware.
Does converting to AVI increase the file size much?
It can — AVI itself doesn't mandate a specific compression method the way modern formats do, and it's commonly used with less efficient, sometimes uncompressed video, so a video converted to AVI can end up notably larger than the same footage in a well-compressed MP4.
Is this private, and does the video get uploaded anywhere?
No — conversion happens entirely in your browser, so the video is never uploaded to a server; it's also free, with no sign-up and no limit on how many files you convert.
Why did Microsoft build AVI, and why does it still linger in some workflows?
AVI (Audio Video Interleave) was Microsoft's fast, competitive answer to Apple's QuickTime — released in November 1992, just under a year after QuickTime brought digital video to the Macintosh, as the centerpiece of a package called Video for Windows. Its defining trick, interleaving audio and video data so both stayed in sync during playback, was a genuine achievement on early-1990s PC hardware, and Microsoft bundled it free with Windows 3.1 before building it directly into Windows 95. Decades of software, from professional editing suites to industrial recording equipment, were built assuming AVI as a baseline format during that era of dominance — long enough that some of those systems are still quietly running today, which is exactly why converting back to AVI is still occasionally necessary.
Is MP4 to AVI free to use?
Yes. MP4 to AVI is completely free, with no sign-up and no usage limits.
Do I need to install any software?
No. MP4 to AVI runs directly in your web browser — nothing to download or install.
Is my data kept private?
Everything happens on your device. We never receive or store the file or text you enter into MP4 to AVI.