Play at your own pace
Choose a difficulty, keep candidate notes and continue an unfinished game saved in this browser.
Play SudokuAbout the site
A clear space for Sudoku.
Sudoku Slate brings playing, learning, checking and printing into one free Sudoku website. No account is needed to start.
One place to play and learn
Sudoku is a small set of rules with room for careful thought. Sudoku Slate keeps the grid readable, the controls close by and the next step easy to find. You can play a quick puzzle, spend longer with a harder one or put the screen away and solve on paper.
Share a daily puzzle
Everyone gets the same puzzle for the same UTC date. Your completion record stays on your device.
Open daily SudokuUnderstand an answer
Use illustrated lessons to learn candidates and singles, or check whether a set of clues has one valid completion.
Browse the lessonsTake a puzzle to paper
Create clear printable sheets in A4 or Letter, with an optional answer key on a separate page.
Print a SudokuPuzzles with an explained method
The current catalog contains 512 puzzles generated for this site. Each has a checked unique solution and a reproducible difficulty rating based on the logical techniques used to solve it. The catalog is finite, and puzzles repeat after its documented cycle.
The lessons use worked examples with specific cells, candidate sets and conclusions. The solver distinguishes conflicting clues, no solution, multiple solutions and one unique answer. It does not disguise a random completion as the answer to an ambiguous puzzle.
Read our puzzle and difficulty methodsAvailable without an account
Core games, tools and introductory guides are available in eight languages. Additional research and technique guides are available in the languages shown in each page’s language menu.
Games, notes, display preferences and completion records are stored in your browser. There is no account-based backup or cross-device sync. Read the privacy page for the details and your choices.
Behind the site
For corrections, accessibility feedback or questions, contact contact@sudokuslate.com. Including the page address and puzzle ID helps us locate the issue.