MCA File

What are MCA files and how to open them

Are you having problems opening a MCA file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your MCA files.

What is a MCA file?

A .MCA file is a Minecraft Anvil file.

Minecraft Anvil File (.mca) is a data file used by Minecraft Java Edition to store saved world terrain. Each .mca file holds a region - a square area consisting of 32 by 32 chunks (each chunk is 16×16 blocks horizontally and covers the full vertical build range) - which together with other regions forms the world map. These files include terrain blocks, entities (mobs, items), metadata like biomes and lighting, heightmaps, and timestamps for when each chunk was last modified.

Minecraft itself creates these files automatically when you save a world using its Java Edition; they replace the older "MCR" / MCRegion format. Players or utilities like NBTExplorer open or edit them - for example, to modify terrain or inspect what objects are stored in specific chunks. .MCA files are located in a world's region folders (for Overworld, Nether, End), and their filenames encode the region's coordinates, such as "r.8.20.mca".

Internally, each .mca file begins with an 8 KiB header divided into two 4 KiB tables: the first maps 32×32 chunk offsets into the file, the second stores 32×32 timestamps of last updates. Following the header are chunk data sections: each chunk's data is stored in compressed NBT (Named Binary Tag) format, preceded by a big-endian 4-byte length field. Data not filling a 4 KiB sector is padded to align with sector boundaries.

How to open MCA files

We have identified one MCA opener that is compatible with this specific type of MCA file.

Programs that open Minecraft Anvil files

Last updated: August 9, 2026

Various apps that use files with this extension

These apps are known to open certain types of MCA files. Remember, different programs may use MCA files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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