Rubik's Cube 4x4: Revenge

"Rubik's Cube 4x4: Revenge" (also called "Master Cube") is a tougher version of the classic Rubik's Cube that can stump even experienced solvers. The puzzle is a 4×4×4 cube, which makes it much harder than the original 3×3. Along with the 8 familiar corners, you get twice as many edge pieces and full 4-piece centers on each of the six faces instead of a single fixed center like on the classic cube.

The most common way to solve it is the reduction method. First, you build the 2×2 center blocks and 2×1 edges on every face. Then you treat these built parts as single pieces, reduce the puzzle to a virtual 3×3×3 cube, and finish it with regular 3×3 algorithms. Because this cube has an even number of layers, there are no fixed center pieces, so center blocks must not only match by color but also end up on the correct faces.

How to play?

This puzzle has over 7.4×10⁴⁵ possible states, millions of times more than a standard Rubik's Cube. The game starts with a solved cube. Use the "Shuffle" button to scramble it automatically, the "Reset" button to return it to the solved state, and switch to full screen for a larger view.

Rotate the cube's faces with your mouse or by dragging on the screen, turning horizontal and vertical layers to line up solid colors on every side. If you get stuck or lose track of your algorithms, hit reset and start a new solve. This is an official speedcubing puzzle, and top players finish it in under 20 seconds. Try to set a new high score or beat your best time.