Add MP4 files
Choose non-empty .mp4 videos up to 100 MB each.
Free online MP4 to MKV converter
Turn MP4 videos into new MKV files.
Add MP4 files up to 100 MB, run Fileverses’ fixed server-side FFmpeg conversion, then review and download each newly encoded MKV result.
- Files not stored
- Sequential MP4 queue
- 100 MB each
Processed by our self-hosted conversion engine
Supported files
MP4 in. H.264 MKV out.
MP4MKV
Add readable MP4 videos up to 100 MB. Each result is a new H.264 MKV with AAC audio when the source has a first audio stream.
How it works
MP4 in. A new MKV out.
Create MKV results
Start the queue to encode each readable source as a new H.264 MKV, with AAC audio when the source includes audio.
Review and download
Check each completed result, then download its separately named MKV file.
Limits and quality
A new encode, not an MP4 container swap.
The route maps the first video stream and optional first audio stream, removes metadata and chapters, then re-encodes H.264 video and AAC audio. Size and visual quality can change.
Convert MP4 to MKVMP4 inputs up to 100 MB
The source must be a non-empty .mp4 file that host FFmpeg can read.
New encode, not a remux
Every successful output is a newly encoded MKV with H.264 video and AAC audio when source audio exists; output size and visual quality can differ from the input.
First streams and fixed settings only
The route uses the first video stream and optional first audio stream, removes source metadata and chapters, and offers no trim, resize, codec, bitrate, quality, or stream-selection controls. Jobs run sequentially.
MP4 to MKV FAQ
Questions, answered.
What MP4 files can I convert to MKV?+−
Fileverses accepts non-empty .mp4 files up to 100 MB each. FFmpeg must be able to read the selected source.
What does the converted MKV contain?+−
A successful result is a new MKV with newly encoded H.264 video and AAC audio when the input has audio.
Is this a lossless MP4-to-MKV conversion?+−
No. This route re-encodes the selected streams rather than only changing the container, so size and visual quality may vary.
Will all tracks, subtitles, chapters, and metadata be kept?+−
No. The conversion uses the first video stream and optional first audio stream. Metadata and chapters are removed; subtitles, alternate tracks, and attachments are not promised.
Can I trim, resize, or choose quality settings?+−
No. This route has a fixed FFmpeg profile and no editing, resizing, bitrate, codec, quality, or stream-selection controls.
Can I convert more than one MP4?+−
Yes. Add supported files to the queue; Fileverses processes server conversions sequentially and supplies a separate MKV download for each successful item.