VisualCubing
Learn to read 4×4 formulas
If you already know 3×3, there's only one new idea here: the 4×4 has two layers per side, so besides turning one face you can turn both at once, or just the inner one. Try each move on the cube and see what moves.
Rw turns both layers together and 2R only the inner one. Lowercase isn't used on 4×4.Try the notation on a real cube
Press a move and watch the cube turn. Drag to look at it from another angle.
Accepts faces (R), wides (Rw), inner layers (2R) and cube rotations (x y z). Lowercase is rejected: the message tells you which to write.
A 40-move scramble with faces and wides, competition-style. Without wides the centers and double edges would never move.
What you can do here
' reversed and ² a half turn.Get to know the 4×4's pieces
The 4×4 has 56 visible pieces split into three types. Two of them will sound familiar from the 3×3; the third one changes everything.
Three types of piece
Corners
Three colors each, same as on the 3×3. They're the only pieces that behave exactly the same on both cubes.
Double edges
Every edge from the 3×3 splits here into two twin pieces. You need to pair them up before you can treat them as a single edge.
Centers
Four per face, and none of them is fixed. Unlike the 3×3, no center here decides on its own what color that face ends up: you have to build them.
The color scheme
Just like on the 2×2, with no centers there's no fixed piece to tell you which color belongs to each face, so you have to carry the scheme in your head: with yellow on top, going left to right it's blue, red, green and orange. The two drawings below show the two pairs of side colors — cycle them with the y button on the module above until they come to you without thinking.
Two ways to solve it
The core idea of the two methods you'll find in Learn is the same: reduce the 4×4 to a regular 3×3. What changes is how interleaved the steps are.
Reduction
Centers, then edges, then a regular 3×3 plus two new parity cases. 4 well-separated steps: the most intuitive way to start.
Professional method (Yau)
Same ingredients, but interleaved on purpose to save moves. It's the one used by almost the entire world speedsolving top — faster, a bit more to learn upfront.