Expert Sudoku for 2026-05-21

Expert Sudoku puzzle published on 2026-05-21, with 30 given clues. Solving it requires the following techniques: Hidden Single, Naked Single, Pointing Pair, Pointing Triple, X-Wing, Naked Triple, Naked Pair, 2-String Kite, XYZ-Wing, Finned X-Wing, XY-Chain, Unique Rectangle, Skyscraper, Swordfish. Every puzzle on this site is generated by Dancing Links and then verified by a tiered human-style solver, so it is guaranteed solvable with logic alone – no guessing or backtracking.