MKV to MP4 converter

Convert MKV to MP4 online — free

MKV won't play on your phone or smart TV? Convert to universal MP4 in one click.

Convert MKV to MP4 free
MKV to MP4 conversion before and after

How to convert MKV to MP4

1

Upload your MKV file

Any Matroska video file, up to 500MB.

2

Select "Convert format"

FixTheFile converts to MP4 using FFmpeg.

3

Download your MP4

Plays on iPhone, Android, smart TVs, and browsers.

Why FixTheFile

Fast, reliable MKV to MP4 conversion

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Universal playback — MP4 works everywhere MKV doesn't — phones, TVs, social media.
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No VLC or codec packs — Convert directly in your browser.
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Free first fix — No signup required to try.
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Keeps audio and subtitles — Standard tracks are carried over during conversion.
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Private processing — Files are never reviewed by humans.
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Also compresses video — Shrink the MP4 afterward if it's still too large.
FAQ

MKV to MP4 — common questions

How do I convert MKV to MP4 for free?

Upload your MKV to FixTheFile and select Convert format — it downloads as MP4.

Why won't MKV play on my phone or TV?

Many phones, smart TVs, and browsers don't support the MKV container natively — MP4 is far more universal.

Will video quality change?

FixTheFile re-encodes the video stream; quality is preserved at a comparable bitrate.

What's the max file size?

Up to 500MB per upload.

Can I convert to other formats too?

Yes — MOV and WEBM are also available from the same tool.

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Try it now

Ready to get started?

No software needed. Works on any device. First fix is free.

Convert MKV to MP4 free
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