Sudoku Holic

Ten thousand sudoku puzzles, and not one of them wastes your time.

Every puzzle has exactly one solution and a symmetric clue pattern, so the board always looks composed and always solves cleanly. Five difficulties, two thousand puzzles each — and the difficulty means something specific.

FIVE DIFFICULTIES, SORTED BY TECHNIQUE

• Easy — naked and hidden singles alone will finish it
• Medium — adds locked candidates (pointing and claiming)
• Hard — adds naked and hidden subsets: pairs, triples, quads
• Expert — adds X-Wing, Swordfish, XY-Wing, XYZ-Wing
• Master — adds chain reasoning: simple colouring, XY-chains

You are never asked to guess. Every puzzle yields to logic.

LEARN THE TECHNIQUES

Ten illustrated lessons, drawn on real boards: naked pair, hidden pair, pointing, claiming, X-Wing, Swordfish, XY-Wing, XYZ-Wing, XY-chain, simple colouring. Read one, then go find it in a puzzle. That is where the difficulty names above stop being decoration.

STUCK? OPEN ONE CELL

Pick the square you are stuck on and spend a hint — it opens that one square and tidies the pencil notes around it. You choose where the help lands, so the rest of the puzzle stays yours.

Not sure whether you have gone wrong somewhere? A board check tells you how many numbers are out of place. It does not say which ones — that part is still your job.

BUILT FOR LONG SESSIONS

• Pencil notes that clean themselves up as you place numbers
• Fill every candidate at once when you want to think in pencil
• Undo as far back as you like
• Three hearts per board — lose them all and the board goes quiet, so you finish on your own
• Pick up exactly where you left a board, even weeks later

PLAYS OFFLINE

Your progress, times and scores live on your device and nowhere else. No account, no sign-in, no sync. Subway, plane, basement — it all works.

TRACK HOW YOU IMPROVE

Daily streak, solved counts, best and average times per difficulty, and a curve of your recent solves. Watch the same difficulty get faster.

FITS YOUR SCREEN

Phones, tablets, and foldables. Unfold and the board moves to one side with the controls beside it — the board never sits across the hinge.

Six languages: English, Korean, Japanese, German, Spanish, Simplified Chinese.

Free to play. Optional short videos refill hints and hearts — never required to finish a puzzle.

Recent changes:
Improved ad stability so rewarded ads load more reliably.
Internal improvements.