Install J2B MC #
Install Fabric Loader for 1.21 (plus Fabric API if the downloads page asks for it), place the JAR in your mods folder, and launch with the Fabric profile.
- Install the J2B MC mod for your 1.21.x version.
- Toggle Bedrock gameplay mode from the in-game menu.
- Explore the /j2b command suite.
- Try joining a Bedrock server as connectivity matures.
Working with J2B MC #
Product-specific steps, separate from the general install guide above.
Bedrock-ify a world
Use the **Bedrock-ify button at world creation**, or toggle it later on an existing world so Bedrock mechanics apply in Java.
Join Bedrock servers
Connect Java → Bedrock directly:
/j2b connect <host> <port>Which mechanics change
161 sub-systems across 13 phases (combat, physics, movement, mob AI, redstone, enchanting…). Each is governed by one of 27 flags — open the config screen (B key or Mod Menu) to pick what you want.
Folder locations by platform #
| Platform | mods / resourcepacks folder | config folder |
|---|---|---|
| Windows | %appdata%\.minecraft\mods · \resourcepacks | %appdata%\.minecraft\config |
| macOS | ~/Library/Application Support/minecraft/mods | ~/Library/Application Support/minecraft/config |
| Linux | ~/.minecraft/mods · ~/.minecraft/resourcepacks | ~/.minecraft/config |
MultiMC / Prism users: these folders live inside Instances/<instance>/.minecraft/. Match the build to your exact Minecraft version — the compatibility table in the docs lists every supported version.
Configure #
Settings live in the config folder (JSON5 files you can edit by hand) and, where available, in the in-game settings screen the mod adds. The exact keys and keybinds are listed in the documentation and the FAQ below.
Tips for J2B MC #
- Keep J2B MC on the version range shown on its product page.
- If it doesn't load, confirm the JAR is in the right mods folder for the launcher and version you chose.
- Bedrock Edition, mobile, and console can't run Java Edition mods or packs — for a port or custom variant, request a commission.