Sudoku

Key Features

A calm Sudoku app for iPhone and iPad: no interruptions, no network required, and a fresh puzzle whenever you want one.

• 🚫

  No In-Game Ads

  Pure focus without intrusive interstitial video ads. Stay with the board from the first digit to the last.

• ✈️

  100% Offline Mode

  Play anywhere during flights, commutes, or zero-connectivity spots. Puzzles stay on your device.

• 💡

  Smart Hints & Undo

  Helpful logical steps without spoiling the answer. Undo a move, mark notes, and keep going.

• 📅

  Daily Challenges & Streaks

  One new puzzle each day. Finish today’s board and keep your completion streak. The first week is beginner-friendly.

• 🎓

  Sudoku Academy

  Basic lessons are free and walk through the rules on the board. Intermediate and advanced technique lessons are part of Sudoku Premium.

• No ads during play
• Offline

How to Play Sudoku

Sudoku is a classic 9×9 logic puzzle. Fill the board so each row, column, and 3×3 box contains the digits 1–9 once. Play has no ads during a game, puzzles stay on your device, and you can play fully offline.

1. 1

   Rows, columns, and boxes

   Place digits 1–9 so no digit repeats in any row, column, or 3×3 box. Given clues cannot be changed.

2. 2

   Four levels, one daily puzzle

   Choose Easy, Medium, Hard, or Expert. Daily Challenge gives you one new puzzle each day and keeps your completion streak. The first week is beginner-friendly.

3. 3

   One logical path

   Every standard puzzle has one solution. Use notes, matching-number highlights, optional error checks, undo, and a timer when you want them.

Sudoku Tips & Solving Techniques

Learning how to solve hard Sudoku starts with three reliable scans. Naked singles clear easy boards. Hidden singles and elimination carry you through Medium, Hard, and Expert.

1. 1

   Naked Single

   Look at an empty cell and cross off every digit already used in its row, column, and 3×3 box. If only one digit remains, that cell is a naked single — place it. Repeat after every placement, because one filled cell often creates the next.

2. 2

   Hidden Single

   Pick a digit that is still missing from a row, column, or box. If only one empty cell in that unit can legally hold it, the digit is a hidden single even when the cell still has other candidates. Place it, then update the rest of the board. This is the technique that unlocks most “stuck” easy and medium puzzles.

3. 3

   Elimination Strategy

   Pencil in every legal candidate, then remove digits that already appear in the same row, column, or box. On harder puzzles, watch for pairs: when two cells in a unit can only be the same two digits, those digits are eliminated from every other cell in that unit. Patient elimination is how to solve hard Sudoku without guessing.

Support & FAQ

Need help with Sudoku? These answers cover difficulty, hints, and how to report a bug.