| MP4 | AVI | |
|---|---|---|
| Compression | Lossy | Lossy |
| Metadata | ✓ | - |
| Open / royalty-free | - | - |
| Defined by | MPEG / ISO | Microsoft |
| Since | 2001 | 1992 |
| Best for | sharing video with anyone, anywhere | legacy Windows players |
MP4
H.264 video and AAC audio. Plays on absolutely everything.
AVI
The classic Windows container. Large files, universally readable.
Questions
MP4 or AVI: which is smaller?
It depends on the content; see our measured benchmarks on the conversion pages.
Can I convert MP4 to AVI?
Yes, in your browser, nothing uploaded.
And AVI to MP4?
Yes, as well.