- Home
- Minecraft World Editors
- MCA JSON
On the recordRead 9 Oct 202612 facts
MCA JSON
Plans and prices
MCA JSON
Free
Open-source command-line tools and JavaScript library for MCA/Anvil and NBT files
Read 9 Oct 2026 · github.com
On the record
- Browser support
- The library has no Node-specific tooling requirement and can be bundled for browser environments; it is published as ES modules only.github.com · read 9 Oct 2026
- Compression
- The library reads chunks compressed with zlib, gzip, LZ4, or no compression, while modified chunks are saved with zlib.github.com · read 9 Oct 2026
- Installation
- The maker documents global or project installation with npm and says Deno, Bun, pnpm, and other package managers can also be used.github.com · read 9 Oct 2026
- JSON size
- The maker notes that an example mostly untouched region produced about 1 gigabyte of JSON and documents compact and condensed output options.github.com · read 9 Oct 2026
- Library
- The TypeScript library provides typed classes and methods for parsing and modifying MCA files, NBT files, and SNBT strings.github.com · read 9 Oct 2026
- Minecraft edition
- Only Minecraft Java Edition is supported; Bedrock Edition uses a different format.github.com · read 9 Oct 2026
- Purpose
- MCA JSON provides command-line tools and a JavaScript library for converting Minecraft Anvil and NBT files to JSON, converting back, and modifying data.github.com · read 9 Oct 2026
- Read limitation
- Chunks larger than 1 MiB stored in separate .mcc files and chunks using custom compression cannot be read, though they can still be listed and removed.github.com · read 9 Oct 2026
- Runtime
- The library works with Node.js 20 and newer.github.com · read 9 Oct 2026
- Support
- For problems with other Minecraft versions, the maker asks users to supply a test MCA file and problem description or submit a pull request.github.com · read 9 Oct 2026
- Tools
- Its command-line tools convert MCA and NBT to JSON, list chunks, find signs, remove chunks, and read player locations.github.com · read 9 Oct 2026
- Version coverage
- The maker says region structure and NBT reading work across versions and reports trying files from Minecraft 1.2.1 through 1.21.github.com · read 9 Oct 2026
