N-Queens Visualizer
Place N queens on an N×N board so that none attacks another — the classic testbed for backtracking search. Watch the algorithm work row by row: it places a queen, greys out every square she attacks, and when a row has no safe square left it backtracks, undoing earlier choices. Choose the board size, slow the animation down, and count the dead ends — the 8×8 board has 92 solutions hiding among 4.4 billion arrangements.
Runs 100% in your browser — simulations are computed locally on your device.
Read the full guide to this tool
Notes
- Backtracking prunes entire subtrees the moment a partial placement fails — that is its whole power.
- Solutions exist for every N except 2 and 3.
- The 8-queens puzzle has 92 solutions, 12 up to rotation and reflection.
- Runs 100% in your browser — simulations are computed locally on your device.
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