How do MP4 and AVIcompare? Here's everything you need to know to choose the right format — and how to convert between them.
MPEG-4 Part 14
MP4 is the most widely used video format in the world. It's the default for everything from YouTube to TikTok, smartphones to streaming services. If you need one video format that works everywhere, MP4 is it.
Audio Video Interleave
AVI is one of the oldest and most recognized video formats. While it has been largely superseded by MP4 and MKV, AVI files are still commonly found in legacy video libraries and older applications.
| Specification | MP4 | AVI |
|---|---|---|
| Full name | MPEG-4 Part 14 | Audio Video Interleave |
| Extension | .mp4 | .avi |
| MIME type | video/mp4 | video/x-msvideo |
| Category | Video | Video |
| Developer | ISO / Moving Picture Experts Group | Microsoft |
| Year introduced | 2001 | 1992 |
MP4 is the universal standard — it works everywhere. AVI has its niche: legacy video archives. When in doubt, convert to MP4 for maximum compatibility.
Need to switch formats? Convert for free with SquishConvert.