Format comparison
MKV vs AVI
By Suprabhat Updated How we write these
The short answer
MKV is the modern choice: it holds any codec, several audio tracks, subtitles and chapters, and handles HD video properly. AVI dates from 1992 and is tied to older codecs like DivX and Xvid, so the only reason to keep one is an old DVD player or TV that reads nothing else.
Matroska Video
Choose MKV when
- Films with several languages or subtitle tracks
- HD or 4K video in H.264, H.265 or AV1
- Archiving recordings with chapters
Audio Video Interleave
Choose AVI when
- An old DVD player or TV only reads DivX AVI
- Very old editing software
- A project that already uses AVI throughout
Side by side
| Property | MKV | AVI |
|---|---|---|
| Full name | Matroska Video | Audio Video Interleave |
| Compression | Lossy | Lossy |
| Usually contains | H.264 or HEVC video with AAC, AC-3 or Opus audio, often plus subtitles | MPEG-4 Part 2 (DivX or Xvid) video with MP3 audio |
| Typical size | Depends entirely on the codec inside | Often two to three times the size of a modern MP4 |
| Support | Patchy | Legacy |
| Opens on | VLC, Plex, Kodi and many smart TVs, but not iPhones, most editors or social apps | Windows Media Player and VLC; no browser or iPhone plays it |
| Best for | Films and series with several languages and subtitle tracks | Old Windows software and hardware players that expect it |
| Introduced | 2002 | 1992 |
Watch out with MKV
Converting an MKV to a single-track format keeps only one audio track and drops soft subtitles unless you pick them.
Watch out with AVI
AVI is only a wrapper. The same extension can hide DivX, Xvid, MJPEG or uncompressed video, which is why one AVI plays and the next doesn’t.
Questions
Is MKV better than AVI?
MKV is the modern choice: it holds any codec, several audio tracks, subtitles and chapters, and handles HD video properly. AVI dates from 1992 and is tied to older codecs like DivX and Xvid, so the only reason to keep one is an old DVD player or TV that reads nothing else.
Which is smaller, MKV or AVI?
MKV is usually smaller for the same content. MKV: Depends entirely on the codec inside. AVI: Often two to three times the size of a modern MP4.
More format comparisons
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MP4 vs MOV: which should you use?
MP4 and MOV usually contain exactly the same video, so quality isn’t the difference. MP4 plays on everything and is what websites and apps expect; MOV is Apple’s format, best kept for editing in Final Cut or iMovie. - Format comparison
MP4 vs MKV: which should you use?
MKV can hold almost anything, including several audio languages and subtitle tracks, which makes it ideal for a media library. MP4 holds less but plays on phones, browsers, editors and social apps, so it wins whenever a video is shared. - Format comparison
MP4 vs WEBM: which should you use?
WebM is the open format made for the web, and VP9 or AV1 inside it can be smaller than H.264 in MP4. MP4 is still the more compatible choice: it plays on iPhones, TVs and in every editor and social app. - Format comparison
AVI vs MP4: which should you use?
AVI is a 1990s container that usually holds older, less efficient codecs, so the same video is often much larger and won’t play on phones or in browsers. Convert AVI to MP4 unless an old device or program specifically needs AVI.