MKV to MP4 — No Upload, No Watermark

Why convert MKV to MP4?

MKV is the enthusiast's container: multiple audio tracks, subtitles, chapters, anything goes. That flexibility is exactly why smart TVs, phones and browsers refuse it — MP4 is the version of the same film they will actually play.

MKV is an open container that can hold almost any codec plus multiple audio tracks, subtitles and chapters. Enthusiasts love it; browsers, phones and TVs frequently refuse it.

When MKV → MP4 is the right move

Playing a downloaded film on a smart TV, console or phone.
Uploading to a platform that rejects the Matroska container.
Importing footage into an editor with no MKV support.

Quality, size and what changes

When the video inside is already H.264 or H.265, the streams are carried over and quality is untouched. Extra audio tracks and soft subtitles do not survive the move to MP4, so the primary track is what you keep.

What you gain with MP4: Plays everywhere, streams well and is hardware-accelerated on virtually all devices.

How it works

Drop your MKV file above and Morphio decodes it locally, then re-encodes it as MP4 using WebAssembly + the browser's native codecs. Nothing is ever uploaded — your files stay on your device. Batch as many files as your machine can handle. See exactly how in-browser conversion works.

MKV to MP4 — frequently asked questions

How do I convert MKV to MP4 without uploading the file?

Open the MKV to MP4 page, drop your video on the drop zone and press convert. Morphio runs an FFmpeg build compiled to WebAssembly that runs inside the page, so the MKV data never leaves your device and no server ever receives a copy.

Does converting MKV to MP4 lose quality?

Audio and video tracks are re-encoded together, so the result stays in sync and plays on standard players. Converting MKV to MP4 only rewrites the container and encoding you asked for — the source file on your disk is never modified.

Is the MKV to MP4 converter free, and how big can the file be?

Yes. The free plan covers 10 conversions a day with files up to 200 MB and adds no watermark or sign-up. Morphio Pro ($5/month, or $29 once for lifetime access) removes the daily cap and raises the per-file limit to 5 GB.

Do subtitles carry over?

Soft subtitle tracks embedded in the MKV are not preserved in the MP4 — keep the .srt file separately if you need them.

Is quality lost?

Not when the codecs are already MP4-compatible; the video stream is passed through as it is.

MKV to MP4 Converter

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