Master Sudoku Online

Master sudoku is the second-hardest tier on Sudoku247 — a step beyond Expert and one rung below Evil. With only 18 or 19 starting numbers, you'll need to lean on advanced techniques: pointing pairs, naked triples, X-wing, and careful candidate tracking just to make a dent in the early game. Master puzzles reward patience. There is always a logical next step, but it's rarely the obvious one — you'll often spend several minutes ruling out possibilities before a single digit clicks into place. Every puzzle is freshly generated and solvable by pure logic; no guessing is required at any stage. If Expert is starting to feel routine, Master is the natural escalation. Stuck? Toggle Notes on, hit Show Candidates to fill in the obvious pencil marks, and look for the one cell whose constraints rule out every digit but one. If Master is too much, the switcher above takes you back to Expert or Hard. If it's not enough, give Evil a try.