Free Apps. Enjoy and Master Sudoku

Sudoku Uno Family of Apps

Enjoy endless Sudoku fun. Sudoku Uno can create a seemingly unlimited number of Sudoku grids for you to solve.Sudoku Duo on iPad allows you to partner up with a second player or challenge an opponent to solve a Sudoku grid while both of you use the same iPad.

The Sudoku Uno apps know how to solve Sudoku puzzles. They apply the same techniques you would use.This gives Sudoku Uno the unique ability to explain the reasoning behind the hints it gives you. The hints thus will not only help you win the game,but will also help you improve your skills.

Worried about damaging your sudoku puzzle with eraser marks? When you play our free online sudoku game, there's no need! You can choose easy sudoku, medium sudoku, or even sudoku for experts if you are confident. You can place notes, find sudoku tips, manage the timer and save the sudoku game by clicking the menu bar in the top-right corner.

• UNO is a fun online card game for 1 player. Play the super popular game UNO online with your best friends or versus the computer. For those who don't know the rules: you start with 7 cards. You must match the number or color of the card on the middle, leaving one on top of it. If you can't match it, you pick one card.
• Play sudoku puzzles online for free. Different sudoku puzzle levels, easy sudoku, medium sudoku, hard sudoku. Print sudoku for free.

Since Sudoku Uno knows what techniques are needed to solve a given grid, it can assess the skill level needed.You get to chose between three levels of difficulty: easy, medium & hard.

• Difficulty levels are determined by techniques to master, not by number of givens
• Unlimited number of Sudoku games
• Green & red pencil notes
• Optional automatic pencil notes
• Intelligent hints with explanations
• High scores

Free Software

The Sudoku Uno and Duo apps are available for free from the Apple App Stores. There are no ads or in-app purchases. No strings attached.

If you love Sudoku Uno, please leave a review and check out our other products.

Game of Sudoku

A Sudoku board is grid of 9 × 9 cells. These are grouped into 9 blocks of 3 × 3 cells.
The goal of the game is to fill the cells of the grid with the digits 1 through 9 so that:

• Each row contains each digit exactly once
• Each column contains each digit exactly once
• Each block contains each digit exactly once

Sudoku games start with a partially filled grid. Your task is to fill in the remaining cells. This should be done by deduction only.A well-formed Sudoku has only one solution and that can be found by logic reasoning.

Sudoku Solving Techniques

At the core of Sudoku Uno is a Sudoku solver that relies solely on “human logic”. It solves Sudoku boards by applying the same techniques you would use.Sudoku Uno can thus be sure that a board can be solved. Knowing which techniques are needed in the process, it can also assess the difficulty level of the game.What’s more, Sudoku Uno can offer helpful hints when you get stuck: it will tell you which technique to apply and which steps to take.

Easy: Single Candidate

When for a given cell all but one candidates have been ruled out, the candidate value should be written to the cell.

Easy: Single Position in Row

When in a given row a given digit is candidate to only a single position, the candidate value should be written to the cell.

Easy: Single Position in Column

When in a given column a given digit is candidate to only a single position, the candidate value should be written to the cell.

Easy: Single Position in Block

When in a given block a given digit is candidate to only a single position, the candidate value should be written to the cell.

Easy: Conjugate Pairs

When 2 cells in a given group (row, column or block) have only 2 candidates, and when those candidates are identical for both cells,those digits can be eliminated as candidates from all other cells in the group.

Medium: Pointing Pairs in Row

When within a given block a digit can only occur in one row, that digit may be eliminated as candidate elsewhere in that row.

Medium: Pointing Pairs in Column

When within a given block a digit can only occur in one column, that digit may be eliminated as candidate elsewhere in that column.

Medium: Block Reduction in Row

When in a given row all candidate positions for a given digit are within the same block, the digit may be eliminated as candidate to any other cell in that block.This technique eliminates the same candidates as 'Pointing Pairs in Row.'

Medium: Block Reduction in Column

When in a given column all candidate positions for a given digit are within the same block, the digit may be eliminated as candidate to any other cell in that block.This technique eliminates the same candidates as 'Pointing Pairs in Column.'

Hard: Hidden Pair in Row

When two digits are candidates to exactly two cells within a given row, all other candidates may be eliminated from these cells.

Sudoku Uniqueness

Hard: Hidden Pair in Column

When two digits are candidates to exactly two cells within a given column, all other candidates may be eliminated from these cells.

Hard: Hidden Pair in Block

When two digits are candidates to exactly two cells within a given block, all other candidates may be eliminated from these cells.

Hard: X-Wing in Row

When a digit is candidate to two cells in two rows and both candidates share the same column, all other instances of that candidate may be eliminated from the two columns.

Hard: X-Wing in Column

Sudoku Universal

When a digit is candidate to two cells in two columns and both candidates share the same row, all other instances of that candidate may be eliminated from the two rows.

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Sudoku Universe

• Sudoku X Miniby Number Puzzles, Inc.

  This small puzzle packs a punch: going beyond the average Sudoku, the X through the middle of Sudoku X Mini is a no-repeat zone.

• Sudoku Dailyby Andrews McMeel Syndication

  Sudoku Daily is a puzzle that uses numbers instead of words. It's a grid of 81 squares, divided into nine blocks of nine squares each. Some of the squares contain a digit. The goal is to fill in the empty squares so that the digits 1 through 9 appear just once in every row, column and individual block.

• Sudoku X

  Sudoku X is Sudoku with a twist - the X through the middle of the puzzle can't have any repeated numbers!

• United Sudoku High Fives Sundayby Knight Features

  Sudoku features a square puzzle consisting of nine rows and nine columns, which together form nine 3x3 mini-squares within the overall layout.

• United Sudoku Triples Sundayby Knight Features

  Sudoku Triples consists of three standard Sudoku panels, sharing one set of 3x3 boxes.

• United Sudoku Sunday Classicsby Knight Features

  Sudoku Sunday Classics are identical to the daily version, specifically the Thursday and Friday versions, which are the most challenging.

• Universal Sudoku Monsterby David Bodycombe

• Universal Sudoku Monster — Spanishby David Bodycombe

• Beach Sudokuby iWin

  It's Sudoku, but on the beach! Give your brain a workout and develop your skills with this entertaining number puzzle game.

• iWin Sudoku Classic en Españolby Andrews McMeel Syndication

• Sunday Sudoku Pacificby Andrews McMeel Syndication

  Fill in every row, column and 3x3 box in the 9x9 grid using the numbers 1-9 with no repeats. Play Sudoku Pacific and see for yourself why the original Sudoku puzzle is a global phenomenon!

• Universal Sudokuby Andrews McMeel Syndication

  Universal Sudoku (9) is the most popular and widely played Sudoku puzzle in the world. Daily delivery keeps players coming back.

• Sudoku Kidsby David Bodycombe

  A Sudoku challenge just for kids! Place the digits 1-6 in each column, row and 2x3 grid, with no repeats.

• Sudoku Wordby David Bodycombe

  Complete the grid so that every row, column and 3x3 box contains the specified letters in some order. One row or column contains a hidden word - can you find it?

• Sudoku Pacificby Andrews McMeel Syndication

  Fill in every row, column and 3x3 box in the 9x9 grid using the numbers 1-9 with no repeats. Play Sudoku Pacific and see for yourself why the original Sudoku puzzle is a global phenomenon!

• Sudoku Classic en Españolby Andrews McMeel Syndication

  Sudoku es un crucigrama que utiliza números en lugar de palabras. Es una cuadrícula de 81 cuadrados, divididos en nueve bloques de nueve cuadrados cada uno.

Sudoku Universe

• Beach Sudokuby iWin

  It's Sudoku, but on the beach! Give your brain a workout and develop your skills with this entertaining number puzzle game.

• Universal Sudokuby Andrews McMeel Syndication

  Universal Sudoku (9) is the most popular and widely played Sudoku puzzle in the world. Daily delivery keeps players coming back.