biomed vs MCA JSON

biomed is a free Minecraft biome editor for Java world saves containing level.dat and a region directory. Choose a biome and use Fill or Draw tools to apply it on the map, then switch between biome and map views. Its Fix Snow/Ice tool melts snow and ice in warm biomes and adds it in cold biomes. Open a savegame through File > Open World or select the map’s region directory manually; save edits through File > Save. The editor supports region editing and batch operations, but not terrain or entity editing. It runs on Linux, macOS, and Windows and requires GTK 2.x. Precompiled downloads are listed for 64-bit Linux and 32-bit Windows. The software is free under the MIT license, which permits use, modification, distribution, and sale subject to its conditions. The license provides the software as-is and disclaims warranty. The README advises backing up maps before editing.

MCA JSON is a command-line toolkit and TypeScript library for handling Minecraft Java Edition region and data files. Its commands convert MCA and NBT data to JSON and back, list chunks, find signs, remove chunks, and inspect player locations. The library supplies typed methods for parsing and changing MCA, NBT, and SNBT data. The maker reports region structure and NBT reading across versions, with files tried from Minecraft 1.2.1 through 1.21. It reads zlib, gzip, LZ4, and uncompressed chunks; changes are saved with zlib. Installation is documented through npm, with Deno, Bun, pnpm, and other package managers also usable. The library can be bundled for browser use, is distributed only as ES modules, and requires Node.js 20 or newer. It supports Java Edition, not Bedrock. Separate .mcc chunks over 1 MiB and chunks using custom compression cannot be read, though they can be listed and removed. A largely untouched region produced about 1 gigabyte of JSON in an example; compact and condensed output options are documented. The software is free.