About MKV to MP4
MKV is a container, not a codec. It can hold almost anything: H.264, HEVC, VP9, several audio tracks, subtitle files and chapters. That flexibility is why screen recorders, downloaders and encoding groups use it, and also why a TV that cannot read Matroska refuses to play a perfectly good video.
Converting to MP4 narrows the stream down to what mainstream players expect: H.264 video and AAC audio. This converter decodes the first video and audio streams from your MKV on the server and writes a new MP4, so codec surprises inside the original container no longer matter. Subtitle tracks are intentionally left out because most MP4 players would not render them.
What this tool does
Container conversion, not guesswork
Whatever codec sits inside the MKV, the server decodes the video and audio and re-encodes them into the standard H.264 and AAC pair used by MP4.
Compatibility with TVs and phones
The output is the same MP4 profile used by the MP4 Converter tool, chosen because it plays on the widest range of devices and platforms.
Simple quality presets
High, balanced and small presets let you trade detail for file size without understanding bitrates, CRF values or encoder settings.
Subtitle tracks cleanly dropped
Matroska subtitle tracks are not muxed into the MP4, which avoids the missing text, broken timing and unsupported-track warnings that trip up simple players.
Preview before saving
The converted MP4 is shown in a built-in player so you can check that the right section converted before downloading the file.
Automatic cleanup
The MKV upload and the MP4 result are stored in a temporary folder only and deleted automatically after the download completes.
How to use MKV to MP4
- 01
Choose your MKV file
Drop the .mkv file into the workspace or browse for it. The limit is 100 MB per file.
- 02
Set the output quality
Balanced suits most videos. Pick high for detailed footage and small when the MP4 needs to be easy to share.
- 03
Convert the container
Click Convert to MP4. The file uploads, the server re-encodes it, and the progress is shown while the job runs.
- 04
Download the MP4
Check the player preview, then save the MP4. Its name keeps the original basename with the .mp4 extension.
Supported formats and limits
- Input
- MKV
- Output
- MP4
- Processing
- Server-side FFmpeg job in a temporary directory, deleted after download.
- Maximum size
- Up to 100 MB
- Requirements
- Chrome, Edge, Firefox or Safari · Server-side FFmpeg conversion
Limitations worth knowing
- Accepts .mkv files only, up to 100 MB per upload.
- Subtitle tracks and additional audio tracks are dropped; only the first video and first audio streams are kept.
- The output is always re-encoded, so it is not a fast container-only remux.
- Jobs are capped at three minutes; long or 4K MKV files may time out.
Privacy and file handling
Your MKV file is uploaded to a temporary directory on our server, converted to MP4 with FFmpeg, and streamed back to you. Both files are deleted automatically when the download finishes; no copy is stored, indexed or shared, and no account is needed.
Read the full privacy policy