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2019 Top 6 Video Converters Online/Offline to Convert MP4 to MKV for Free

Laura Goodwin Convert Video

I got this OLD anime show and it has subs. It's an MP4 but I want to turn it into MKV so I can play it smoothly on WMP, but I also want to keep the option to turn on and off the subtitles.

Does this problem also haunt you? Do you want to play MKV video on your Samsung Blu-ray player or 4K TV? Or you want to enjoy high-quality entertainment?

No need to worry about that. As we all know, MP4 video is not as clear as MKV video. You can turn your MP4 to MKV easily. A MKV converter will help you solve this problem. We shall provide 6 useful MKV converters for you to free convert MP4 to MKV, including online and offline.

MP4 to MKV Converter Free

Part 1. MP4 video format VS MKV video format

You should know some differences between MP4 and MKV. Check this below.

MP4 is a commonly used video format that stores audio and image. MP4 files can be played on iPhone, iPad, iPod, Android devices, Apple TV, Xbox One, PSP, etc. It is usually compressed into smaller format with medium quality.

MKV is a universal format that contains some multimedia content, like movies and TV shows. MKV are supported on some Blu-ray player and TV media. MKV is a high-definition video format. If you want to enjoy a high quality movie, you can convert MP4 to MKV.

Though MP4 is the most popular video format, MKV has better audio and video quality than MP4. As for file size, MKV file is usually larger than MP4 file at the same quality for high resolution. If you want to convert an anime, HD video, TV show, etc. in MP4 to other formats, you can choose MKV format as the export file.

Part 2. Best MP4 to MKV converters online version for free

If you want to convert MP4 to MKV, the easiest way is to use an online video converter. Here are 4 best and free online MKV converters for you.

Vidmore Free Online Video Converter

With the simple user interface, Vidmore Free Online Video Converter can help you convert all video and audio formats, including MP4, MKV, AVI, WMV, MOV, FLV, MP3, M4A, etc. at ease.


Easy to use and 100% free converter to turn MP4 into MKV with only three steps.

Support iPhone, iPad, Samsung, Sony, LG, TV, DVD player, PSP, Xbox, etc.

Customize output MKV files by adjusting video codec, resolution, bitrate, sample rate, etc.

Fast convert any MP4 videos or audios on Windows and Mac OS without size limitation.


Simple to use and support batch conversion.


Cannot crop and trim the video.

How to convert MP4 to MKV with MKV online converter

Step 1. Click “Add files to convert” to launch MKV converter on your computer.

Add files to convert

Step 2. Click “Add File” to load the MP4 file on your computer. Choose MKV as the export format.

Add file

Step 3. Browse the destination folder where the exported file will be saved. Them, click “Convert”.

Conversion complete

Online Convert - Convert Video to MKV format

This Matroska MKV converter enables you to frees convert MP4 video files to MKV format. You just need to load the MP4 file or enter a URL. Then click “Convert file” and choose screen size, video bitrate, audio quality, audio codec, and more.

MKV Converter


Free Convert different formats like MP4 to MKV, AVI to MKV, 3GP to MKV, WMV to MKV.

Optional settings include choosing screen size, change video bitrate, video/audio quality, video/audio codec, frame rate, pixels, etc.


Easy to operate and change MP4 to MKV.


The supported input formats are limited.

Online UniConverter

Online UniConverter ( is a free MP4 to MKV converter. You can convert MP4 file to any other formats, including MP4 to MKV, MP4 to AVI, MP4 to WMV, MP4 to MOV, MP4 to VOB, etc.

Online UniConverter


Convert video or audio files to other formats online for free.

Support various popular formats like MKV, AVI, WMV, VOB, MP4, etc.


The conversion is slow. You can’t add more than 2 files to convert at the same time.

Free Online Video Converter is a free online video converter web. You can just convert MP4 to MKV from a video URL or a file. The supported videos include MP4, MKV, AVI, MPG, MOV, WMV, FLV, 3GP. It supports audios include MP3, AAC, W4A, FLAC, WAV, OGG, WMA.

Free Online Video Converter


It is simple to convert files or videos from YouTube, Facebook, Viemo, and more to many video formats in high quality.


Lack of editing functions.

Part 3. Best MKV converters on desktop version for free

If you want a MKV converter with multiple functions, you can choose a free video converter for desktop. We provide you 2 free MP4 to MKV converters for you here.

Aiseesoft Free Video Converter

Aiseesoft Free Video Converter is an all-featured MKV converter for free. It allows you to convert 300+ videos between MP4, MKV, M4V, MOV, WMV, AV and FLV, MPG, TS, 3GP, FLV, ASF, VOB, etc.

Aiseesoft Free Video Converter


Free convert MP4 to MKV on Windows 10/8/7 and mac OS High Sierra/mac OS Mojave.

Edit MKV videos with various settings and enhance video resolution and remove background noise.

Compatible with devices like iPhone, iPad, iPod, Samsung, HTC, Apple TV, Sony, LG, etc.

Customize your own video such as title, author, time, etc. before sharing it on YouTube.


This software comes with more than 225 preprogrammed conversion and optimized files.


Lack of tool to burn your converted videos to DVD.

Freemake Video Converter

Freemake Video Converter ( is the free software to convert nearly 500+ formats like MP4, AVI, WMV, DVD, FLV, MKV, MP3, etc.

Freemake Video Converter


Support all popular and rare non-protected video and audio formats.

Add streaming clips from YouTube, Facebook, Vimeo, Dailymotion, Vevo, etc.

Compatible with iPhone, iPad, Android devices, Samsung, Nokia, Huawei, PSP, Xbox One, etc.

Automatically load video and audio files to iTunes and iOS.


Support various input format and edit the video clips. It can burn DVD and Blu-ray.


You need to purchase Gold Pack for faster conversion.


This article mainly introduces you top 6 free video converters for Windows and Mac. You can choose one to turn your MP4 movie to MKV format as to enjoy it on Blu-ray player or TV. You can choose a fee video converter online or offline according to your needs. We sincerely hope that your problem has solved with our suggestions.

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