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MKV to MP4 Converter

Convert MKV videos to MP4 for iPhone, editors and the web. Lossless fast mode when possible. Private.

Free once a day, no account needed. One file up to 25 MB. Unlimited with Image & Media or All Tools.See plans
Your files never leave your device

How to convert MKV to MP4

  1. 1

    Choose your MKV files

    Click the upload area or drag files onto it. Nothing is uploaded — files are opened locally.

  2. 2

    Adjust the settings

    Pick quality, then press the convert button.

  3. 3

    Download the result

    Save each file individually or everything at once as a ZIP.

MKV files often won’t play on iPhones, in video editors or on websites. Convert them to MP4 — if the video is already H.264, it’s repackaged in seconds with no quality loss.

Read the full guide with screenshots

What is MKV?

MKV (Matroska) is a flexible video container that can hold many audio and subtitle tracks. It is common for downloads and recordings, but iPhones, editors and most websites expect MP4.

What is MP4?

MP4 is the most widely supported video format, used by phones, cameras, YouTube and every social platform.

Is it private?

Yes. Unlike upload-based converters, ZapMorph processes files inside your browser tab, so the file stays on your device. It is never transmitted, stored or logged — close the tab and it’s gone.

Frequently asked questions

Is the mkv to mp4 converter free?

Yes, once a day. Convert one file up to 25 MB a day without an account. A free account gets one run a day on any Pro tool with files up to 50 MB; Pro and Lifetime plans are unlimited.

Are my files uploaded to a server?

No. The conversion runs entirely in your browser, so your files never leave your device. We only count how many files you convert — never their names or contents.

What is the maximum file size?

Up to 25 MB per file without an account, 50 MB with a free account, and 1 GB on Pro. Very large files also depend on your device’s memory.

Can I convert multiple MKV files at once?

Yes. Select several MKV files at once — up to 5 on the free plan or 50 on Pro — and download all results in a single ZIP.

Does it work on Mac, Windows, iPhone and Android?

Yes. It works in any modern browser — Chrome, Edge, Firefox and Safari — on desktop and mobile, with nothing to install.

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