In this tutorial we will look at how to split a large MKV file in to multiple parts and in a user specified size. This will keep them in the same container without any loss in quality of audio or video. For this we will require a free program written by the very talented Moritz Bunkus called MKVToolnix. Once you have downloaded (I chose the installer, but the .7zip is there if you prefer) the program which for Windows users can be found at the bottom of the page, install it.
First select your language
Click Next
Select the install path, by default it will be C:\
Now click Install
You will now be asked if you wish to add a shortcut for the program on your Desktop
In the next window, you will be asked if you wish to use a GUI (graphical user interface) for MKVExtract. For the purposes of this tutorial, we are just splitting a .mkv file, and a GUI is included for this purpose. Click Next
That’s the install finished. Next we will move on to the main window.
When the program first opens, you will be greeted with the main window, with the Input tab selected. Click add and navigate to the mkv file that you wish to split. Highlight the file and hit Open.
The file information will now be loaded. At the bottom you can also specify the path for the outputted files. I chose to keep then in the same folder, which is what it will default to.
Next click on the Global tab, and check the Enable Splitting box. Just under this, make sure that …after this size: is selected and input the size of the largest split file that you require. Now for me, I wanted to enable the mkv to be played on a FAT32 file system, so it will have to be less than 4GB. I chose 3800M (MB) as my preferred split file size, but note that they may come out slightly larger so avoid choosing 3950M as that may run over the 4GB mark, which is what you want to avoid. Please note that you have to specify a size identifying letter after the numerical size:
- G = Gigabyte (GB)
- M = Megabyte (MB)
- K = Kilobyte (KB)
Once you have selected your split file size, simply click Start Muxing at the bottom.
The program is very quick to work, but this will vary depending on your hardware specs.
Hopefully, you should have now successfully split your mkv file into separate files that will play in FAT32 file systems or for whatever reason you wanted to split them.
As you can see from the output folder, my 11.5GB.mkv file has now been split into 3 separate files. The video and audio quality is just as crisp, and the splits are spot on
Please note, that in this tutorial I was running Windows 7 Ultimate x64 with 4GB RAM on an Intel Core 2 Quad Q6600.
Logichaos also have a great tutorial on splitting MKV files that will also aid you in splitting files for YouTube, as well as having a great FAQ
MKVToolnix is available on the following platforms:
- Arch
- CentOS/RedHat
- Debian
- Fedora
- FreeBSD
- Gentoo
- Mac OS X
- Mandriva
- NetBSD
- Slackware
- openSUSE
- Ubuntu
- Windows
- Zenwalk
- others
Well, I hope this has been of use to some of you. This program is simply fantastic and very quick, and has a ton of other features which I haven’t gone into, so have a play around. Any questions, please feel free to ask in the comments.














