What happens when you convert MP4 to MKV
| Inside a typical MP4 | H.264 or HEVC (H.265) video with AAC audio |
|---|---|
| Copy without re-encoding | Yes, almost always: MKV accepts any codec, so streams are copied in seconds |
| When re-encoded | H.264 video with AAC audio |
| Extra tracks | Your file's first video and audio track are kept |
| Opens in | VLC, mpv, Plex and most smart TVs; browsers, iPhones and editors often do not |
Sizes are typical values; your files will vary with content and settings.
MP4 MPEG-4 Part 14
MP4 is the universal video container. With H.264 video and AAC audio it plays on every phone, browser, smart TV and social network, which makes it the safest choice for sharing.
MP4 converterMKV Matroska Video
MKV is an open container that can hold almost any codec plus multiple audio tracks and subtitles. It is popular for archived films and series.
MKV converterHow to use the MP4 to MKV Converter
- 1
Choose a MP4 file or drop it onto the page.
- 2
Review the video options. The defaults suit most files.
- 3
Click Convert and download your MKV when processing finishes.
Why convert MP4 to MKV?
MP4 is what phones, cameras, screen recorders and most video sites produce. Editing software sometimes prefers intra-frame formats like ProRes for heavy editing. Choose MKV to repackage video without re-encoding, since it accepts any codec.
Frequently asked questions
Will the MKV lose quality?
Both formats are lossy, so converting re-encodes the data once more. Using a high quality setting keeps the generational loss very small. Avoid converting the same file back and forth repeatedly.
Does converting MP4 to MKV re-encode the video?
Yes, almost always: MKV accepts any codec, so streams are copied in seconds. A typical MP4 contains H.264 or HEVC (H.265) video with AAC audio. Otherwise the result is H.264 with AAC audio.
Questions about privacy, file-size limits or conversion speed are answered in the general FAQ.