Format comparison
MP4 vs MKV
By Suprabhat Updated How we write these
The short answer
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.
MPEG-4 Part 14
Choose MP4 when
- Sending, uploading or posting a video
- Playing on phones and in browsers
- Editing in common video software
Matroska Video
Choose MKV when
- Films and series with several languages or subtitles
- Archiving with every track kept
- Playback in VLC, Plex or Kodi
Side by side
| Property | MP4 | MKV |
|---|---|---|
| Full name | MPEG-4 Part 14 | Matroska Video |
| Compression | Lossy | Lossy |
| Usually contains | H.264 or HEVC video with AAC audio | H.264 or HEVC video with AAC, AC-3 or Opus audio, often plus subtitles |
| Typical size | 1080p phone video runs roughly 60–130 MB a minute | Depends entirely on the codec inside |
| Support | Opens everywhere | Patchy |
| Opens on | Every phone, browser, TV, editor, chat app and upload form | VLC, Plex, Kodi and many smart TVs, but not iPhones, most editors or social apps |
| Best for | Sharing video anywhere | Films and series with several languages and subtitle tracks |
| Introduced | 2003 | 2002 |
Watch out with MP4
An MP4 that won’t play is rarely broken; it usually holds a newer codec such as HEVC or AV1 that the player doesn’t support.
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.
Need to switch?
Convert in your browser in a few seconds. Nothing is uploaded, and there is no size limit.
Questions
Is MP4 better than MKV?
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.
Which is smaller, MP4 or MKV?
They are about the same size for the same content. MP4: 1080p phone video runs roughly 60–130 MB a minute. MKV: Depends entirely on the codec inside.
How do I convert MP4 to MKV?
Use the free MP4 to MKV converter. It runs in your browser, so the file is never uploaded.
How do I convert MKV to MP4?
Use the free MKV to MP4 converter. It works the same way, entirely on your device.
More format comparisons
- Format comparison
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 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. - Format comparison
MKV vs AVI: which should you use?
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.