🧠 Expert · 26 given numbers · ID expert-15
Expert Sudoku No. 15
A expert puzzle with exactly one solution. Techniques needed: naked single, hidden single, pointing pair, box/line reduction, naked pair, hidden pair, hidden triple, forcing chain.
The sheet below is exactly what prints on one A4 or Letter page. Choose “Save as PDF” in the print dialog if you prefer a file.
Keyboard: arrow keys to move, 1–9 to fill, Backspace to erase, N to switch notes.
Solution (hidden until you want it)
Stuck, or checking a finished grid? Reveal the answer, or open the printable solution page to keep the answer sheet separate.
Generate a new puzzle
About this puzzle
Expert puzzles need at least one top-tier technique: naked or hidden quads, Swordfish or a forcing chain (testing a two-candidate cell and following the consequences). Looking for a different challenge? Easy, Medium or Hard puzzles are on the printable Sudoku page.
Need a break from the numbers?
Try a hard riddle
Sudoku and riddles train the same muscle: spotting what must be true. Here are a few hard riddles with answers.