MP4 to MKV Converter

When you need MP4 to MKV

MKV is a flexible container that can hold multiple audio tracks, subtitles in various formats, and chapters for navigation in a single file. That is exactly why it is chosen for home media libraries, film collections with dubs, and materials for media servers like Plex, Jellyfin, or Kodi.

If you have an MP4 with a single track and no subtitles and you want to add a translation or dub as a separate file, MKV is a convenient container: everything is stored together and nothing gets lost when moving to another device.

It is worth understanding that MKV is a container, not a special encoding method. The video track is re-encoded during conversion, so quality depends on the source file: a blurry MP4 will not become a sharp MKV, and the file size is usually comparable to the original or slightly larger.

What changes after conversion

You get the same clip in an MKV container. The picture will be the same as in the original MP4 - conversion does not improve quality. The container changes, which makes it possible to add extra tracks and subtitles later using dedicated tools.

Some MP4 features may not carry over to MKV - for example, embedded chapters or additional tracks from the source. For a simple clip with one audio track this usually does not matter.

MKV compatibility is broader than AVI but narrower than MP4: most modern computer players and media servers open MKV without issues, but not all TVs and home players support it.

When this is especially useful

• A movie with multiple dubs needs to be stored in one file rather than keeping several MP4 files.
• Materials for a media server: Plex, Jellyfin, Kodi work well with MKV and can switch tracks directly in the interface.
• Adding subtitles to video without losing them when the file is moved to another device.
• An archive of a video collection in an open format not tied to a specific program.

Common tasks and search situations

• convert MP4 to MKV with subtitles;
• convert video for Plex or Jellyfin media server;
• make an MKV with multiple audio tracks;
• movie in MKV for home theatre;
• video with subtitles in one file;
• convert MP4 to MKV for Kodi;
• add subtitles to a clip via MKV.

What to check before converting

1. Make sure your player or device supports MKV - not all TVs can read it.
2. Assess the source file: conversion does not fix quality problems or damage.
3. If you need extra tracks or subtitles, prepare the relevant files in advance.
4. Check the finished MKV on the target device, not just on a computer.

Format and conversion limits

MKV is supported by most computer players but not all TVs and home devices. Before converting the entire collection, make sure the device you plan to watch on actually reads MKV.

Adding extra tracks or subtitles directly in our converter is not possible - the service converts the container from MP4 to MKV. Advanced track work requires separate tools.

If the file is damaged or protected, conversion may not complete.

Related tasks

If the device does not open MKV, see MP4 to AVI - AVI is understood by many old players. For editing video in Apple apps, MP4 to MOV is a better fit. If you need to publish a clip on a website - MP4 to WebM.