MP4 to MKV Converter

Convert MP4 to MKV online. MP4 and MKV are containers, while the video and audio codecs live inside them. Free batch processing with no signup or watermark.

Upload your videos

How to convert MP4 to MKV

  1. 1

    Add one or more MP4 files. You can review the complete batch before processing it.

  2. 2

    MKV is already selected for this page. Add multiple videos and adjust the available video and audio codec settings before processing.

  3. 3

    Start the batch, then download and check the finished MKV file or files.

What changes when you convert MP4 to MKV?

MP4 and MKV are containers, while the video and audio codecs live inside them. Compatible streams may be copied; otherwise they are re-encoded for the selected MKV settings.

  • For the widest playback support, check that the selected video and audio codecs are accepted by the device or service that will receive the MKV file.
  • Add multiple videos and adjust the available video and audio codec settings before processing.
  • Open the finished MKV file and check fine details, layout and compatibility in the app where you plan to use it.
Source format

What is a MP4 file?

MP4 is a widely supported container for video and audio. Compatibility and file size depend on the codecs and settings used inside it, which is why MP4 with H.264 video and AAC audio is a common choice for sharing and uploading.

How to open a MP4 file

MP4 is widely supported by browsers, phones, smart TVs and desktop players. Playback still depends on the video and audio codecs stored inside the file.

Output format

What is a MKV file?

MKV (Matroska) is a flexible open container that holds high-definition video, multiple audio tracks and subtitles in one file. It is popular for movies and archiving, but is not natively supported by every device or browser.

How to open a MKV file

MKV plays in VLC and most modern media players; some phones, browsers and TVs need it converted to MP4 first.

Frequently asked questions

Is it free to convert MP4 to MKV?
Yes. There is no sign-up, subscription or watermark on the converted file.
What happens to quality when MP4 becomes MKV?
MP4 and MKV are containers, while the video and audio codecs live inside them. Compatible streams may be copied; otherwise they are re-encoded for the selected MKV settings.
Which conversion options are available on this page?
Add multiple videos and adjust the available video and audio codec settings before processing.
How can I open the converted MKV file?
MKV plays in VLC and most modern media players; some phones, browsers and TVs need it converted to MP4 first.

Convert MP4 to other formats

ToolSpice can convert your MP4 files to these other formats:

MP4 Converter
MP4 to MOV
MP4 to AVI
MP4 to FLV
MP4 to TS
MP4 to 3GP
MP4 to WAV
MP4 to OGG

Convert other formats to MKV

These other formats can be converted to MKV on ToolSpice:

MKV Converter
MOV to MKV
AVI to MKV