5  /  637 Reviews
Apr 4, 2020 Last updated


Older Versions

# Change Log

# Version 45.0.0 "Heaven in Pennies" 2020-04-04

## New features and enhancements

* mkvmerge: mkvmerge has never supported appending & splitting FLAC audio

tracks. mkvmerge will now emit error messages when the user attempts either

instead of continuing and creating invalid FLAC tracks.

* MKVToolNix GUI: added an option in the preferences to turn on eliding text

on tab headers. If enabled, tab names will be shortened so that all tab

headers fit into the window's width. Implements #2768.

* MKVToolNix GUI: added an option in the preferences to disable all tooltips.

* MKVToolNix GUI: Windows: debug output sent via Qt's to Windows' debugging

facility will use a more verbose message format including the application

name, making it easier to filter for in SysInternal's "Debug View" utility.

* MKVToolNix GUI: multiplexer: if the file identification fails due to a JSON

parser error, the output generated by `mkvmerge` will be output via Qt's

debugging facility (viewable with SysInternal's "Debug View" utility on

Windows; on other systems it's output on `STDERR`) allowing insight into

what's gone wrong.

* MKVToolNix GUI: multiplexer: if an error occurs during file identification,

the name of the processed file will be mentioned in the error message.

* MKVToolNix GUI: multiplexer: if an error occurs during identification of

multiple files, the GUI will ask the user whether to continue or abort the

identification process. Implements #2778.

* MKVToolNix GUI: job queue: added an option in the preferences for removing

completed jobs when exiting the program depending on their status.

Implements #2769.

## Bug fixes

* mkvmerge: H.265/HEVC packetizer: fixed changing the NALU size length, it was

using the wrong offset into the `hevcC` structure.

* mkvmerge: MP4 reader: fixed calculating the duration of video tracks that

only contain a single frame. Fixes #2747.

* mkvmerge: MP4 reader: if there's no frame offset table (`ctts` atom) present

for H.265/HEVC video tracks, mkvmerge will determine the timestamp order

itself instead of relying on the timestamps in the MP4 being in the

presentation order required by Matroska. Fixes #2777.

* mkvpropedit: Windows: mkvpropedit wasn't caching when reading the file to

modify, slowing down operations such as adding track statistics tags

considerably. Fixes #2761.

* MKVToolNix GUI: multiplexer: when using the title as part of the destination

file name (both automatically as well as using the "copy title to

destination file name" function) all characters that aren't valid in a file

name are replaced by hyphens.

* MKVToolNix GUI: multiplexer: the "copy title to destination file name"

function was broken when the "make file name unique" option in the

preferences was disabled. In that case the file base name was removed

regardless of what the title was set to at the time.

* MKVToolNix GUI: multiplexer: when using the "show command line" menu option

on Windows the path to the `mkvmerge` executable was shown with forward

slashes instead of backslashes. This is a purely cosmetic fix as Windows

supports both forward and backward slashes.

* MKVToolNix GUI: multiplexer: when adding Blu-ray playlists the GUI used to

only look for the English version of the disc library information (title &

cover images). Now the GUI will present all disc library entries in the

"select playlist to add" dialog & let the user chose which one to use (if

any). Fixes #2765.

* MKVToolNix GUI: multiplexer, info tool: fixed the "warn before overwriting"

check wrt. jobs creating the same file. Fixes #2758.


MKVToolNix is a small collection of tools (mkvmerge, mkvinfo, mkvextract, mkvpropedit and mmg) that allows you to manipulate Matroska (MKV) files in several ways.

You can use MKVToolNix to create, split, edit, mux, demux, merge, extract or inspect Matroska files. The program will also work with other video formats (AVI, MPEG, MP4, MPEG, Ogg/OGM, RealVideo, MPEG1/2, h264/AVC, Dirac, VC1) including some video codecs (such as VP9 video codec support - reading from IVF/Matroska/WebM files, extract to IVF files). Audio formats (AAC, FLAC, MP2, MP3, (E)AC3, DTS/DTS-HD, Vorbis, RealAudio) and also most subtitle formats (SRT, PGS/SUP, VobSub, ASS, SSA, etc.). MKVToolNix is a cross-platform application that will work on Windows® (both 32 and 64-bit versions), Mac® OS X® and Linux. Please note that from this page you can download the Windows® (installer and portable) and Mac® OS X® versions. If you're looking for a Linux version, you can download one from MKVToolNix homepage.

Trademark Note 1: Microsoft®, Windows® and other product names are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries.

Trademark Note 2: Mac and OS X are trademarks of Apple Inc., registered in the U.S. and other countries.

MKVToolNix Review

Note: I tested MKVToolNix on Windows® 7 Ultimate 32-bit using mkvmerge GUI and several other tools opened from the Command Prompt such as mkvinfo. Therefore, if you're looking for more information on how to compile MKVToolNix yourself, check the README file (online). I wanted to test two things: the mkvmerge GUI (software interface) and see how easy or hard is to use the command line for all the other tools such as "mkvinfo."

The software interface (mkvmerge GUI)

As soon as the setup finished, I opened the "mkvmerge GUI" shortcut from my desktop. At a first look, the interface seems quite intuitive, so my first action was to open an MKV file, select an option and see the result. I went to program interface at the "Input" tab and used the "Add" button (it also works using the "drag and drop" method. 

I selected a 710 MB MKV file and I wanted to split this (from "Global" tab - select "Split Mode" - "split after size" and then I specified the size - in this case 50M = 50MB) in smaller files with a size of 50 MB for each. Finally, I clicked on "Start Muxing" button. 

The program required just 45 seconds for this operation, and the result was 14 smaller MKV files. After this, I wanted to mux the content of an AVI file in MKV format. Again, I went to "Input" tab and used the "Add" button, I selected an AVI file from my computer, and I noticed that the program displayed the Output filename automatically with the name of the same file but this time in MKV (Matroska) format. 

Again, the same button called "Start Muxing" was doing all the magic. This time the process was even faster - at the end I could read the following message "Muxing took 34 seconds".

Other command line tools (example: mkvinfo)

To use all the other command line tools in Windows®, open a Command Prompt window. Just hit the "Start" button, click on "Search programs and files" (Windows® 7 and Vista) or "Run" (Windows® XP and others) and type either "cmd" or "command prompt" (without the quotes). 

In the command prompt, you can try each program (mkvmerge, mkvinfo, mkvextract, mkvpropedit) by typing its name and the usage parameters. An example would be: "mkvinfo --help" that will display a list with all the commands available. I tried mkvinfo using this command: "mkvinfo -g" and the result was a small interface that allowed me to open an MKV file and see all kind of technical details about it. I was also able to save the results in the TXT format.


You can launch an instance of mkvmerge GUI (software interface) directly from the command prompt. Just type "mmg" and hit "Enter."

Besides of the usual standard documentation from the command prompt (I hate it because it's hard to read) you can find and read the online documentation available on MKVToolNix documentation homepage here: (use the blue links for mkvmerge, mkvinfo, mkvextract, mkvpropedit and mmg to access the online help).

Final Conclusion

You can learn how to use several main features in minutes but to master the program, it does require more time. Your best bet is to experiment all of his options and whenever you need some help, check the FAQ section (filled with great answers to common issues), start with the guide of mkvmerge GUI here and check the documentation for all the other tools - here (provided once again). MKVToolNix is a "must-have" software if you work with MKV files. It has an incredible amount of features that are not listed on the homepage. Ultimately, if you appreciate this tool, please consider a DONATION to support the work of Mr. Moritz Bunkus, the author of MKVToolNix.

Found this software useful? Please consider a donation to the author.