Convert MP4 to AVI
For the DVD player in the living room and the car stereo that predates smartphones — converted on your device, never uploaded.
Drop your video or audio here
or
MP4, MOV, WebM, MKV, AVI, MP3, WAV and more — any size, no upload
🔒 Files never leave your device — everything runs in your browser.
Nobody converts to AVI for fun — you convert because some stubborn piece of hardware demands it: a DVD player with a USB port, a car entertainment unit, an old TV, industrial equipment, or software from an era when AVI ruled. Those devices don't speak modern H.264 in an MP4 container; they want the classics. This converter produces exactly that: MPEG-4 video (the DivX/Xvid family those devices were built for) with MP3 audio, in a standard AVI container.
Two honest notes before you convert. First, this is a real re-encode into an older, less efficient codec — the AVI will usually be larger than your MP4 at similar quality, which is normal and unavoidable. Second, if your target device is modern and simply shows an error about the file, try MP4 with a different player first; AVI is the answer for old hardware, not a fix for every playback problem.
How it works
- Drop your file
Any common format, any size. Nothing is uploaded — the tool runs in your browser.
- Convert
Compatible files are repackaged instantly with zero quality loss; others are hardware-transcoded at high quality.
- Download
Your converted file is ready on your device — nothing to wait for, nothing to delete from a server.
Frequently asked questions
Why is the AVI bigger than my MP4 was?
MP4 files typically carry H.264 or newer codecs; AVI-era MPEG-4 is about half as efficient, so matching the quality costs more bits. That trade is inherent to targeting old hardware — the file grows so the 2005 chip in your player can decode it.
Will this play on my DVD player or car stereo?
If the device lists AVI, DivX, or Xvid support, very likely — the output uses MPEG-4 video with MP3 audio, the exact combination that generation of hardware was certified for. Check the device's maximum resolution too: many old players cap at 720×576, so consider compressing large videos first.
Is the output compatible with DivX and Xvid players?
Yes — the video encodes as standard MPEG-4 Part 2, the codec that DivX- and Xvid-certified hardware plays natively, with MP3 audio to match. If a device is still picky, keep the resolution at or below what its manual lists — commonly 720×576 for DVD-era players.
Is my file uploaded to a server?
No. ConvertUno runs entirely in your browser on your own device. Your file never leaves your computer or phone — there is no upload at all.
Is it really free, with no watermark?
Yes. Processing happens on your device, so serving you costs us almost nothing — no watermark, no account, no file-size limit, no daily quota.