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A tool to select chunks from Minecraft worlds for deletion or export.
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MCA Selector

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An external tool to export or delete selected chunks and regions from a Minecraft world.



Executing the tool, it shows an empty window with a chunk and a region grid. To actually show a world, open a folder containing Minecraft Anvil (*.mca) files. The tool will then render a top-down view of this world that you can zoom into and zoom out of by scrolling up and down and that you can move around using the middle mouse button (Cmd+LMB on Mac OS).

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Zooming out far enough disables the selection of single chunks but lets you select entire regions.


Upon finishing selecting chunks and regions, they can be deleted or exported using the Selection-menu. Exported chunks and regions are not deleted from the original world.

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A selection (not the chunks and regions themselves) can also be exported or imported and even be applied to different worlds.

Chunk filter

The MCA Selector also contains a powerful tool to delete or export chunks and regions by conditions like the data version, the time it was last updated, how much time players have spent in this chunk and some more. Multiple of these conditions can be used to create a very specific query describing what chunks and regions should be deleted or exported.

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Because the conditions use internal values used by Minecraft, the following table gives a brief explanation on what they do:

Condition Type Description
Group - Groups multiple conditions.
DataVersion int The DataVersion tag of the chunk. 100-1343 for 1.12.2 and below, 1444 for 1.13 snapshots and above.
InhabitedTime long The total amount of time in game-ticks players have spent in that chunk. 1 second ~20 ticks. Also accepts a duration string such as 1 year 2 months 3 days 4 hours 5 minutes 6 seconds.
LastUpdate int The time a chunk was last updated in seconds since 1970-01-01. Also accepts a timestamp in the yyyy-MM-dd HH-mm-ss-format such as 2018-01-02 15:03:04. If the time is omitted, it will default to 00:00:00.
xPos int The location of the chunk on the x-axis in chunk coordinates.
zPos int The location of the chunk on the z-axis in chunk coordinates.
Palette String A list of comma (,) separated 1.13 block names. The block names will be converted to block ids for chunks with DataVersion 1343 or below. The validation of block names can be skipped by writing them in double quotes ("). Example: sand,"new_block",gravel.
Status String The status of the chunk generation. Only recognized by Minecraft 1.13+ (DataVersion 1444+)
LightPopulated byte Whether the light levels for the chunk have been calculated. If this is set to 0, converting a world from 1.12.x to 1.13 will omit that chunk. Allowed values are 0 and 1.

Notice Running the query will check the .mca-file's name first if the query would even apply to any chunk in this file using the xPos and zPos conditions, as long as the query is built in a way that allows doing this.

NBT Changer

The NBT Changer modifies the world files directly by changing specific values.

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You can change the following values:

Field Type Description
LightPopulated byte Whether the light levels for the chunk have been calculated. If this is set to 0, converting a world from 1.12.x to 1.13 will omit that chunk. Allowed values are 0 and 1
DataVersion int Allows to change the DataVersion of the chunks. Should be used with extreme care.
InhabitedTime long This field stores the amount of game-ticks players have spent in a chunk. Impacts the local difficulty.
LastUpdate long Stores a timestamp when this chunk was last updated in Milliseconds.
Status String The status of the chunk generation. Only recognized by Minecraft 1.13+ (DataVersion 1444+)

For more information about the fields have a look at the chunk format description on Minecraft Wiki


The tool creates an image for each region from the provided mca-files. These images are saved separately inside a cache-folder in the working directory of the program for future usage. Experience showed that a Minecraft world with a size of 10GB resulted in cached image files with a total size of 80-100MB. Caching as many regions as possible significantly improves loading times though.


If something is not working properly or if you want to see the exact query that is run using the chunk filter, debugging can be enabled in the settings. It will print useful information about what the program is currently doing to the console.

Supported Versions

The MCA Selector currently supports the following Minecraft versions:

Minecraft Version DataVersion Supported
Beta 1.3 - 1.12.2 100 - 1343 Yes
1.13 - 1.13.2 1444 - 1631 Yes
1.14 1901 - ? Yes

Download and installation

Download Version 1.6


  • Either:
    • JRE 8+, you can get it from HERE
    • A Minecraft Java Edition installation
  • A computer
  • A brain

If you have Java from Oracle installed on your system:

Most likely, .jar files are associated with java on your computer, it should therefore launch by simply double clicking the file (or however your OS is configured to open files using your mouse or keyboard). If not, you can try java -jar mcaselector-1.6.jar from your console. If this doesn't work, you might want to look into how to modify the PATH variable on your system to tell your system that java is an executable program.

If you have Minecraft Java Edition installed on your system:

Minecraft Java Edition comes with a JRE that you can use to start the MCA Selector, so there is no need to install another version of java on your system. On Windows, that java version is usually located in C:\Program Files (x86)\Minecraft\runtime\jre-x64\bin\ and once inside this folder you can simply run java.exe -jar <path-to-mcaselector-1.6.jar>. On Mac OS you should find it in Applications/ where you can execute ./java -jar <path-to-mcaselector-1.6.jar>.

If you are using OpenJDK:

If you are using a distribution of OpenJDK, you have to make sure that it comes with JavaFX, as it is needed to run the MCA Selector. Some distributions like AdoptOpenJDK (shipped with most Linux distributions) do not ship with JavaFX by default. On Debian distributions, an open version of JavaFX is contained in the openjfx package. This or some other installation of JavaFX is required to run the .jar.

If none of these instructions work, apply "A brain" that you providently held ready after having read the "Requirements" section carefully.

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