How do I convert MP4 to MKV online?

Upload a MP4 file, choose the available MKV options, run the conversion, and download the result. The tool is free, supports batches, and accepts server uploads up to 100 MB.

Is Convert MP4 to MKV free?

It is free, requires no account, and adds no watermark. Server uploads are limited to 100 MB per file, and browser-first paths are limited by device memory.

Where is the file processed?

Yes. This conversion uses a server-side engine, so the file is uploaded over HTTPS, processed in an isolated request, and removed after the result is produced.

How do I process a batch?

Queue multiple files, run them together, and download the finished results as a ZIP. Each server file is limited to 100 MB, and large batches may take longer.

Open the downloaded MKV file in the application or database you plan to use, check the structure against the source, and keep the original until the output is approved.

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Convert MP4 to MKV Online

Turn MP4 files into MKV output online. The service is free, requires no account, supports batch queues, and limits server uploads to 100 MB per file. The conversion runs on the server in an isolated request. Keep the original file while you review the converted copy.

Convert .MP4 to .MKV

Select a file to begin. Processing details and limits are listed below.

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How to convert MP4 to MKV

1
Upload MP4 files
Add one or more MP4 files to the queue. The uploader keeps batch items separate.
2
Choose MKV settings
Set the available quality or format options, or keep the defaults for a first pass.
3
Run and save the result
Run the queue and download the MKV files individually or together as a ZIP.

MPEG-4 Part 14 video vs Matroska video

Spec	MPEG-4 Part 14 video	Matroska video
MIME type	video/mp4	video/x-matroska
Format type	video	video
Standard	ISO/IEC 14496-14	Matroska specification
First release	2003	2002
Browser support	All current major browsers for common codecs	Limited; most browsers do not play MKV natively
Contents	Container for video, audio, subtitles, and metadata. Common payloads include H.264, H.265, AV1, AAC, and MP3.	Extensible container for video, audio, subtitles, chapters, and attachments. Common payloads include H.264, H.265, VP9, AV1, AAC, Opus, and FLAC.

About MPEG-4 Part 14 video

Broad device support, efficient streaming, flexible codec choices, and good compatibility with social platforms. Compatibility depends on the codecs inside the container, not only the .mp4 extension; advanced subtitles and chapter support vary.

Format reference

About Matroska video

Open container, excellent subtitle and chapter support, and the ability to hold almost any codec. Hardware and browser support is less consistent than MP4; some mobile and smart-TV apps cannot open it.

Format reference

Why convert MP4 to MKV?

A converted copy separates the delivery format from the original edit or camera file.
MKV is more widely accepted by browsers, phones, TVs, or sharing services than the source MP4 file.
A standardized output makes it easier to archive, upload, or hand a file to someone with different software.
Playback compatibility is usually the main reason to change a media container.

Will quality change?

The conversion standardizes the container and codecs for compatibility. It is a delivery step, not a lossless remux. Check a sample before processing a large batch.

Processing and limits

Processing: Server-side
Engine: FFmpeg
Maximum size: 100 MB per file on the server.
Batch support: Yes, multiple files can be queued; completed results can be downloaded as a ZIP.
Quality controls: Options can adjust output dimensions, audio bitrate.

The file is processed on the server because the conversion requires a server-side engine or a utility operation.

Hardware and browser support is less consistent than MP4; some mobile and smart-TV apps cannot open it.
Check metadata, dimensions, and compatibility after the conversion.
Very large files can hit the 100 MB server limit before conversion starts.

Platform compatibility

MKV works in limited; most browsers do not play mkv natively. Open the result in the app where it will be used, and keep the source MP4 for comparison.

When not to convert

For a one-off preview, a local viewer may be faster than creating a new delivery file.
If MKV support is uncertain on the destination device, test a sample before processing a large batch.
Do not use a converted file as the legal or signed original when signatures or metadata must be preserved.

Frequently asked questions

How do I convert MP4 to MKV online?: Upload a MP4 file, choose the available MKV options, run the conversion, and download the result. The tool is free, supports batches, and accepts server uploads up to 100 MB.
Is Convert MP4 to MKV free?: It is free, requires no account, and adds no watermark. Server uploads are limited to 100 MB per file, and browser-first paths are limited by device memory.
Does MP4 to MKV conversion lose quality?: The conversion standardizes the container and codecs for compatibility. It is a delivery step, not a lossless remux. Check a sample before processing a large batch.
Where is the file processed?: Yes. This conversion uses a server-side engine, so the file is uploaded over HTTPS, processed in an isolated request, and removed after the result is produced.
How do I process a batch?: Queue multiple files, run them together, and download the finished results as a ZIP. Each server file is limited to 100 MB, and large batches may take longer.
What can go wrong?: Open the downloaded MKV file in the application or database you plan to use, check the structure against the source, and keep the original until the output is approved.

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