Tetsudoku

Every Sudoku has a logical path to the end. Tetsudoku teaches you to find it. Four new puzzles arrive each morning, one per difficulty: Easy, Medium, Hard, and Expert. Twenty more come each week. The archive holds every past puzzle, ready to revisit.

Stuck on a move? Most apps hand you the answer. Tetsudoku shows you the next logical step, names the cells involved, and explains the strategy behind it. Head to the Learn section for fifteen solving strategies, each with a full explanation and practice puzzles. Over time, you need fewer hints.

Tetsudoku tracks candidates for you. No penciling in numbers by hand: it computes every possible value for every cell automatically. Tap to highlight all cells that can hold a given digit. Find cells with exactly two candidates in one tap. Choose any combination of values and see which cells share them. Less busywork, more solving.

Spotted a puzzle in the newspaper? Enter it by hand and solve it right here. Unlock Tetsudoku Unlimited to generate custom puzzles at any difficulty, any time.

Stats track your best and average solve times for each difficulty, puzzles finished, and hints used. Watch yourself improve.

Easy puzzles are always free. Tetsudoku Unlimited is a single one-time purchase that unlocks Medium, Hard, and Expert puzzles plus unlimited puzzle generation.