Sudoku

Every puzzle here is generated while you wait, so the grid in front of you is not one somebody else solved yesterday. The score at the end also remembers every shortcut you took. Sudoku is a free logic puzzle you play in your browser. You fill a 9x9 grid with the numbers 1 to 9 so that no row, column or 3x3 block repeats a number.

Key Controls

• Select a cell: LEFT CLICK
• Enter a number: 1 TO 9
• Erase a number: DELETE

How It Works

Sudoku starts with a level choice: Beginner, Intermediate or Advanced. The game then builds a fresh puzzle and fills in a set of starting numbers, up to 38 on Beginner, 32 on Intermediate and 26 on Advanced. Fewer givens means more cells to work out yourself and fewer easy footholds at the start.

You can enter numbers in 2 ways. In Cell First mode you pick the cell, then the number. In Number First mode you pick the number, then tap or click every cell that should hold it. A separate memo mode lets you pencil small candidate numbers into a blank before you commit. A timer runs the whole time, and the final score depends on how fast you finished and which helps you used.

1. Choose Beginner, Intermediate or Advanced on the level screen.
2. Click an empty cell to select it.
3. Type a number from 1 to 9, or press a number button on screen.
4. Switch on memo mode to note candidates you are not sure about yet.
5. Press Delete to clear a number you placed by mistake.
6. Fill every blank so each row, column and 3x3 block holds 1 to 9 once.

What Makes It Stand Out

• 3 levels: Beginner, Intermediate and Advanced each set a different number of starting givens.
• Generated puzzles: The game creates a new grid each time you start, instead of pulling from a short fixed list.
• 2 entry modes plus memo: Cell First, Number First and memo mode cover the 3 common ways people solve on paper.
• A score that tracks help: Autofilling notes halves your score, each hint costs points, and using the solver drops it to 0.
• Time bonus windows: Finishing inside 10 minutes on Beginner, 20 on Intermediate or 30 on Advanced earns bonus points.
• Saved progress: An unfinished puzzle is kept, and the game offers Continue or New the next time you open it.

Getting Started

• Open Sudoku on Beginner first. Beginner gives you the most starting numbers, so most cells can be solved by spotting the single number a row or block is missing.
• Use Number First for scanning. Picking a 7 and then clicking every cell where it fits matches the way most solvers sweep the grid one number at a time.
• Write memos only in tight spots. Pencil marks in a cell with 2 or 3 candidates are useful, but filling every blank with memos turns the grid into noise.
• Finish rows and blocks that are nearly full. A row with 7 numbers placed has only 2 candidates left, which is the fastest progress on the board.
• Save hints for real dead ends. Each hint takes points off the final score, so one hint late in a hard grid costs less than several early ones.

Going Further

Sudoku on Advanced starts with 26 givens or fewer, and that changes how you solve. Singles stop appearing on their own, so memo mode becomes the main tool rather than a backup. Pairs are the next technique to learn: when 2 cells in a row can only hold the same 2 numbers, those numbers can be removed from every other cell in that row. The score rewards discipline more than speed alone, since notes autofill halves the result and the solver or no timer option wipes it out. A clean finish inside the bonus window is the highest score the game can give, which makes Intermediate under 20 minutes a better target than a slow Advanced run full of hints.

Mistakes Worth Avoiding

• Guessing a number to see what happens. One wrong guess spreads through the row, column and block, and the error often only shows up many moves later.
• Autofilling notes out of habit. The shortcut halves your score even if you only needed notes for a single block.
• Turning off the timer. Playing without time sets the score to 0, so it only makes sense for pure practice.
• Ignoring the 3x3 blocks. Many players scan rows and columns only, but a block missing just one number is often the quickest cell to solve.
• Starting a new puzzle by accident. Choosing New over an unfinished saved game replaces it, so pick Continue if you want your progress back.

Similar Puzzle Games

If filling a grid by pure logic is what kept you going, Nerdle swaps the 9x9 board for a hidden math equation that you narrow down with each guess. Meowdoku keeps the one per row and column rule but swaps the numbers for cats on a grid of colored regions. Google Minesweeper is the closest cousin in spirit, a grid where every number is a clue and one careless click ends the round. More picks are in Puzzle Games.

Final Thoughts

The Sudoku game does the basics properly: 3 levels, flexible entry modes and memo notes that work the way paper does. Playing Sudoku online here suits solvers who like a score that punishes shortcuts. Players looking for variants like Killer or Samurai puzzles, or daily challenges, won't find them here.

FAQs About Sudoku

1. What is Sudoku?

   Sudoku is a number logic puzzle played on a 9x9 grid divided into 3x3 blocks. The goal is to fill every blank with a number from 1 to 9 so that no row, column or block repeats a number.

2. How to play Sudoku?

   Click a cell, then type a number from 1 to 9 or press a number button, and use Delete to clear a mistake. Keep filling cells until every row, column and 3x3 block contains 1 to 9 exactly once.

3. What difficulty levels does Sudoku have?

   Sudoku has 3 levels: Beginner, Intermediate and Advanced. Beginner starts with up to 38 given numbers, Intermediate with up to 32 and Advanced with up to 26.

4. Can I play Sudoku on mobile?

   Yes. Sudoku runs in mobile and tablet browsers, where you tap a cell and then a number button to fill it. On a computer you can also type numbers with the keyboard.

5. How does scoring work in Sudoku?

   Sudoku gives bonus points for finishing within a time window of 10, 20 or 30 minutes, depending on the level. Each hint costs points, autofilling notes halves the score and using the solver sets it to 0.

6. Does Sudoku save an unfinished puzzle?

   Yes. Sudoku keeps an unfinished puzzle and offers Continue or New when you return. Choosing New replaces the saved game.