What is a Knight's Tour?
A puzzle where one chess knight must visit every square of the board exactly once. The knight moves in an L shape — two squares one way and one square sideways. That is the whole rule set, but because you can never revisit a square, careless moves quickly trap you in a dead end.
Rules
The knight moves only in an L shape, visited squares are off limits, and touring every square completes the stage. Some chapters add a twist — closed tours where the last move must return to the start (The Way Back), boards that must end on a flagged square (Fixed Endings), boards whose left and right edges wrap around (Wrapped World), and pieces that leap 2×3 instead of a knight.
Strategy — the Warnsdorff rule
Proposed by H. C. von Warnsdorff in 1823, this old heuristic is still the strongest: among the reachable squares, move to the one with the fewest onward options first. The point is to clear squares that isolate easily — corners above all — before it is too late. In Practice mode, turn on Counts to see each square's onward options, and Hint will point to the smallest one.
History
The knight's tour appears in records of the 9th-century Baghdad chess master al-Adli. Leonhard Euler analyzed the problem systematically before the Berlin Academy in 1759, and it went on to become a canonical example of the Hamiltonian path problem in graph theory. The 8×8 chessboard alone has more than 13 trillion closed tours.
Frequently Asked Questions
Is every board solvable?
No. A 4×4 square, for example, has no complete tour, and boards whose two square colors are badly unbalanced are impossible — the knight changes color on every move. The 298 stages on this site only include boards whose solutions were verified by a solver.
I keep hitting dead ends. Any tips?
Visit corners and edges early. Central squares stay reachable, but corners become isolated if you leave them for later. Undo is unlimited, and Practice mode with Hint and Counts is a good place to build intuition.
What makes a closed tour (The Way Back) different?
After visiting every square, your final square must be one knight-move away from where you started, closing the path into a single loop. You have to plan the ending in advance, which makes it a step harder.
Is it free? Do I need to install anything?
Free, no install, no account — it runs right in your browser. Progress (clears, stars, best times) is stored only in the browser you play in.