✦ PLAY IN YOUR BROWSER ✦

Drag the words to change the rules and see what happens!

WORDS

psst — try BUG IS STOP… or steal WIN for yourself

CHANGE THE RULES.

CHANGE THE WORLD.

SOLVE THE PUZZLE.

Rules aren't hardcoded.
You rewrite them.

✦ NOT YOUR AVERAGE PUZZLE GAME ✦

Programming isn't about memorizing syntax. It's about changing the rules.

SOLVE PUZZLES

Challenging levels that teach logic, not syntax.

REWRITE RULES

Move words, change meanings, break expectations.

LEARN BY PLAYING

Understand programming concepts through game mechanics.

HANDCRAFTED LEVELS

31 carefully designed puzzles with multiple solutions.

✦ WHY JAVA IS YOU ✦

Every level is a tiny program. The rules on the board are its statements — push them around and the world recompiles in real time. Walls stop being solid. Flags stop being goals. You stop being you.

Built entirely from scratch in Java and JavaFX — no game engine. A custom rule parser and evaluator, full undo/redo history, particles, sound, and 31 handcrafted levels themed on real computer-science ideas: logic gates, pipelining, linked lists, encapsulation, even git rebase.

It began as a university project and turned into a love letter to Baba Is You — and to the idea that programming is really about changing the rules.

JAVA 24 JAVAFX NO ENGINE 31 LEVELS OPEN SOURCE

The actual title-screen artwork of Java Is You

the game's actual title artwork — every rule on it is real

✦ FAQ ✦

Is this Baba Is You?

It's a loving homage. The word-pushing idea comes from Hempuli's masterpiece Baba Is You — but Java Is You is built completely from scratch in Java, with 31 original levels themed around computer science instead.

Do I need to know Java to play?

Not at all. You learn the ideas by playing: levels are built around concepts like conditionals, loops, inheritance, logic gates and databases. If you already code, you'll grin at the references.

How do I run the game?

On Windows, just grab the .exe — it bundles its own Java runtime. On macOS/Linux, download the JAR plus JavaFX 24, then:

java --module-path /path/to/javafx/lib \
  --add-modules javafx.controls,javafx.fxml,javafx.graphics,javafx.media \
  --enable-native-access=ALL-UNNAMED -jar java_is_you.jar

What are the controls?

Arrow keys / WASD to move every YOU. Z undo, Y redo, R restart, Esc menu. The two boards on this page use the same keys.

I'm stuck on a level.

Stuck is part of the fun — but if a puzzle really has you, there's an official hint book with nudges for every level.