Stable Mods & Challenges v3.2.1

J2B MC

Recreate Minecraft Bedrock Edition inside your Java world — one button. All the mechanics, all the bugs, everything Bedrockified.

Download Documentation Roadmap

Stable · Stable v3.2.1 across 1.21–1.21.11. Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified inside your Java Edition world. 26.x builds are blocked upstream (no mappings).

Why it exists

Purpose

Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified inside your Java Edition world. One press Bedrock-ifies gameplay, physics, combat, mob AI, redstone and more — and lets Java players join Bedrock servers directly, with 161 mechanics across 12 versions, each individually toggleable.

Who it's for

Players curious about Bedrock mechanics without switching editions, and technical players exploring cross-edition connectivity.

Key capabilities

One-button Bedrock

Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified.

Bedrock-ify mode

161 sub-systems across 13 phases: combat, physics, movement, mob AI, redstone, enchanting, food and more.

Join Bedrock servers

Native RakNet client with ECDH + AES-256-CFB8 encryption to connect Java to Bedrock servers.

Toggleable flags

27 config flags (config screen via B key / ModMenu) to control every mechanic.

World import

Import .mcworld files into Java worlds.

Features

Everything J2B MC does

7 features across 5 categories — all real, all working.

One-Button Bedrock 1 feature

Bedrockify your world

One press recreates Minecraft Bedrock Edition inside your Java world — all mechanics, all the bugs, everything Bedrockified.

Mechanics Coverage 2 features

161 sub-systems

161 sub-systems across 13 phases: combat, physics, movement, mob AI, redstone, enchanting, food and more.

Version-validated

Validated across 12 versions with a zero-crash-risk core and feature-parity matrix.

RakNet Connectivity 1 feature

Join Bedrock servers

Native RakNet client with ECDH + AES-256-CFB8 encryption connects Java players to Bedrock servers.

Config Flags 2 features

27 toggleable flags

Control every mechanic from the config screen (B key / ModMenu).

/j2b command suite

Explore and control the mod from in-game commands.

World Import 1 feature

.mcworld import

Import Bedrock .mcworld files into Java worlds.

Getting Started

How to use J2B MC

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.

View the full J2B MC tutorial →

Compatibility

Versions & loaders

Property	Value
Loader / platform	Fabric
Latest version	3.2.1
Minecraft versions	1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, 1.21.11

26.x builds are blocked upstream (no mappings).

Version history

Changelog

3.2.1

2026-08-06 Release Latest

Bridge the gap

161 Bedrock mechanics across 13 phases
RakNet client for joining Bedrock servers
12-version build matrix (1.21–1.21.11)

Warning. Online Bedrock auth is still being verified against real servers

Warning. 26.x builds are blocked upstream (no mappings)

Roadmap

Where it's going

Connectivity foundation

done

Bedrock connection layer, handshake, and encryption.

Real-server connectivity

Xbox Live auth and verified real-server joins.

Full gameplay parity

later

Broaden Bedrock behaviour coverage.

FAQ

Questions, answered

Can I join Bedrock servers?

Yes — the native RakNet client connects Java to Bedrock servers with full ECDH + AES-256-CFB8 encryption.

Does Bedrock gameplay change PvP?

Yes — combat (attack cooldown, knockback, crits), movement, physics, mob AI, redstone and 50+ other mechanics are reworked toward Bedrock.

How much can I control?

Everything — 161 sub-systems across 13 phases are governed by 27 toggleable flags (config screen via B key / ModMenu).

Which versions are supported?

1.21 through 1.21.11. 26.x builds are blocked upstream (no mappings).

Can I import Bedrock worlds?

Yes — .mcworld files can be imported into Java worlds.

Is it safe on servers?

It is validated against all 12 versions with a zero-crash-risk core and feature-parity matrix.

Compatibility & limitations

What to know

Compatibility. 26.x builds are blocked upstream (no mappings).

Status. Stable v3.2.1 across 1.21–1.21.11. Recreate Minecraft Bedrock Edition into your Java world using a simple button — all mechanics, all the bugs, everything Bedrockified inside your Java Edition world. 26.x builds are blocked upstream (no mappings).

Downloads

Get J2B MC

3.2.1 for 1.21.x.

Fabric mod JAR View Tutorial

Ecosystem

Part of something bigger

Every Hero Studios product is engineered to work with the rest of the ecosystem — one design language, one performance bar, one long-term vision. J2B MC belongs alongside these tools.