What is this

Browsercraft makes unmodified Minecraft run in the browser using CheerpJ, a Java runtime for modern browsers.

What this is not

• A replacement for the official Minecraft. The experience is limited to 3 minutes by design, please refer to minecraft.net for the full game.
• Minecraft Classic, an alpha version of Minecraft playable in the browser
• Minecraft Bedrock Edition
• The latest version of Minecraft. Newer releases of Minecraft use a newer version of Java and OpenGL which we currently do not support.
• A modified version of Minecraft. We do not modify the game in any way, we just run the original JARs.
• A reimplementation of Minecraft in another programming language

How it works

CheerpJ is a Java Virtual Machine written in WebAssembly and it runs entirely in your browser. CheerpJ can run any Java application, without modification and without requiring the source code. This demo demonstrate these capabilities by running an older version (1.2.5) of Minecraft and LWJGL entirely in the browser.

This project is a work-in-progress and not everything works yet, but there are no fundamental limitations preventing a complete game experience.

Build with CheerpJ

Interested in using CheerpJ for your own projects? Take a look at the documentation and join the Discord server for questions and support.

You can also sign-up for the first CheerpJ Hackathon. The event theme and precise dates are still being determined, but it will be a week-long competition to be held between September and October 2025, with a £500 prize awaiting the winning team.