Convert MP4 to MKV Online
Upgrade your video container. Convert MP4 to MKV to support soft subtitles (SRT/ASS), chapters, and multiple audio languages in one file.
MP4 → MKV
Why Convert MP4 to MKV?
MP4 is great for playback but limited for features. MKV can hold unlimited video, audio, picture, or subtitle tracks in one file.
Ideal for anime fans and movie collectors who want to preserve original language tracks and fancy subtitles without burning them in.
How to Convert MP4 to MKV
- Upload your MP4.
- We repackage it into MKV.
- Download availability depends on file size.
Key Features of MiConvert MP4 to MKV
- Convert MP4 to MKV for advanced features
- Support for subtitles and chapters
- High-quality video conversion
- Fast, free, and secure
- No software installation needed
- Batch processing supported
Frequently Asked Questions
Is re-encoding needed?
Usually no. We can just copy the video stream into the MKV container, which is instant and maintains 100% quality.
Does it play on VLC?
Yes, VLC and MPC-HC play MKV files perfectly with full subtitle support.
Can I add subtitles later?
Yes, MKV makes it easy to add or remove subtitle tracks later using tools like MKVToolNix.
Is it free?
Yes, completely free.