MKVToolNix is a set of tools that can be used on MKV files, which is a video format that grows ever more present in our daily lives. The application falls into a very crowded niche, and there is not much competition for it. Nonetheless, it’s a useful app, and it would be nice to take a closer look at it.

MKVToolNix has been around for a long time, and many users already know about its existence, but it’s mostly used to identify and read the properties of MKV files (Matroska). At least, this is what I was using it for. The truth is that the application can do more than just tell you details about any particular file, and I want to show you some of these features.

Some of you might wonder what this MKV file format is. Matroska, or MKV for short, is just a container, pretty much like anything else such as MP4, AVI, and so on. The only difference is that it follows an open standard free container format, which makes it all the more interesting for people who want to use it for packaging. It’s also capable of carrying numerous videos and audio sources in a single file, which is very useful if you have something dubbed in multiple languages. If you add the fact that embedding subtitles is possible as well, then you can understand why it’s preferred by so many people.

In addition, i’s easier to understand why you would need a tool like this one. Managing multiple video and audio sources from a single file can be difficult, but with the right application that can be done very easy. It also works the other way around, you can merge multiple video and audio sources into a single one, and explaining why that is incredibly useful is not necessary.

MKVToolNix is a toolset, which means that there is more than one. To be fair, there are three, but soon only two will remain. If you install it right now, you’ll find MKVToolNix GUI, mkvinfo, and mkvmerge GUI. When you open the last tool, you’re informed that it’s going to be deprecated and that its functions are being integrated into the main app.
First of all, mkvinfo is just a small app that tells you everything you need to know about a particular file. Unless you really know how to read that output, it’s not something that regular users will need.

The main app is the MKVToolNix GUI, which seems to be pretty simple, straightforward at a first glance, but looks can be deceiving. You can learn to save other files as MKV files pretty quick and to split videos, but the application is a lot more complex than that. The merging process is a little bit more complicated, and it will take more effort to understand it, especially if you haven’t done anything like that before.

Some very basic video options are available as well, like aspect ratio, resolution, cropping, and a few others, but nothing out of the ordinary. It’s also possible to embed subtitles just by loading a file, and that’s always useful. Another complex task that can be accomplished with MKVToolNix is the addition of chapters, just like you would have for the older DVD format. It takes a little bit of practice, but it’s worth it if you want to make that video file more special.

The speed of the conversion is impressive, but we need to keep in mind that it’s only changing containers. Adding multiple audios sources or video sources will take longer, but MKVToolNix is really, really fast. It’s not the most intuitive application out there. I’ve used dozens of converters and other similar apps over the years, and I know what to expect and what to use, but a regular user might have a little bit more work with it. It’s not the most intuitive interface, and some of the functions need to be researched before being used.

It’s clear that MKV files are here to stay, and MKVToolNix is a perfect set of tools that are aimed at a very specific file format. Its complexity and speed recommends it from the get-go, even if it will take a little bit longer to learn how to use it.