A simple place to play Sudoku
This free Sudoku board is built for straightforward play. The grid works with touch, mouse, and keyboard input, so you can solve on a phone at the kitchen table or on a laptop during a break. Select a square, choose a number, and keep moving through the puzzle. If you select a clue cell, the game keeps it locked because those starting numbers are part of the puzzle.
The difficulty selector lets you move between Easy, Medium, Hard, and Expert without hunting through the site. Easy puzzles are good for learning and quick wins. Medium puzzles are steady daily practice. Hard and Expert puzzles ask for more notes and slower checking. If a puzzle no longer feels fun, use New puzzle and try another level.
Using notes, hints, and checks
Notes mode works like pencil marks on paper. Turn it on, tap a square, and add possible numbers instead of placing a final answer. Good notes are small reminders, not guesses. They help you see when one candidate disappears from a row, column, or box.
The Hint button fills one useful square when you are stuck. The Check button scans the board and tells you whether the current entries match the solution. A mistake counter keeps the session honest without making the puzzle feel harsh. Show solution is available when you want to study the finished grid or compare it with a printed copy.
A good practice pattern
Start each puzzle by scanning for rows, columns, or boxes with many clues. Place the numbers that have only one possible square. After the obvious moves stop, turn on notes for the areas with two or three options. Review your notes after every new placement because one number can remove candidates across the board.
A free Sudoku site should be easy to return to. Sudoku Duck saves your current online puzzle in the browser on the same device, so a short interruption does not end the game. For paper play, use the printable page. For checking a puzzle from somewhere else, use the solver page.