Play sudoku online – daily puzzle and solver
Generate a new puzzle or type in your own, then play with the keyboard or the big number pad – the solver explains each step in plain English. Every puzzle has exactly one solution. There is also a daily sudoku – the same puzzle for everyone.
Source: Wikipedia: Sudoku. Updated: .
How it is calculated
How this sudoku works
A sudoku has 9 × 9 cells in nine 3 × 3 boxes. The goal: every row, every column and every box contains each number from 1 to 9 exactly once. The bold givens are fixed; you fill in the rest.
How to play and solve sudoku online
- Pick a level (Easy, Medium, Hard or Expert) and tap “New sudoku” – or choose “Enter my own”, type in a puzzle from a newspaper or book and press “Use this puzzle”.
- Tap a cell and choose a digit from the number pad, or type 1–9; ✎ or N switches to notes.
- Stuck? “Hint” shows the next logical step, “Check” marks wrong entries and “Solution steps” explains every step to the end.
Example: A puzzle with 26 givens leaves 81 − 26 = 55 empty cells. If row 3 is only missing 4 and 7, and column 5 already has a 7, the empty cell R3C5 must be 4 – the solver calls this a “naked single”.
Daily sudoku
“Daily sudoku” loads today’s puzzle. It is calculated from the calendar date, so everyone gets the same grid – no account, no server. Monday and Tuesday are easy, Wednesday, Thursday and Sunday medium, Friday and Saturday hard; if no hard puzzle with a unique solution turns up for a date, the display shows the actual level. A new one appears at midnight, your device’s time.
Controls
- Phone and tablet: tap a cell, then a number on the big pad below. ⌫ clears the cell, ✎ toggles notes mode, ↶ undoes your last move.
- Keyboard: arrow keys move the selection, 1–9 enters a number, Delete or Backspace clears the cell. N toggles notes, Shift + number adds a note directly, Ctrl + Z undoes.
- Notes: small numbers in a cell track possible candidates. When you place a number, it is removed automatically from the notes in its row, column and box.
- Conflicts: if a number appears twice in a row, column or box, both cells turn red right away. “Check” also compares your entries with the solution and marks wrong ones.
- Show mistakes instantly: Tick the box and every entry that does not match the solution turns red as soon as you type it. Untick it to play without help.
- Share result: After solving, the button sends your time with a link that opens exactly this puzzle – for “Daily sudoku” and for Easy, Medium and Hard. The clock carries on after a reload and pauses while the tab is in the background.
The sudoku solver: steps with explanations
“Hint” shows the next logical step, “Solution steps” shows every step to the end. The solver works like a person and always uses the simplest technique that makes progress:
- Naked single: only one number is still possible in a cell.
- Hidden single: a number fits in only one place in a row, column or box.
- Pointing and claiming: if a number inside a box is limited to one row, it cannot appear in the rest of that row – and vice versa.
- Pairs and triples: if two (three) cells share exactly two (three) candidates, those numbers are removed from the rest of the unit.
- X-Wing: if a number sits in two rows only in the same two columns, it is removed from those columns everywhere else.
- Backtracking: when no technique helps, the computer tries values systematically. This only happens with very hard puzzles and is shown in the steps.
Difficulty levels
The level depends on the hardest technique needed: Easy uses singles only, Medium adds pointing, claiming and pairs, Hard adds triples and X-Wing, Expert needs more than these. Every generated puzzle is checked before you see it: it has exactly one solution. The givens are placed symmetrically, as in newspaper puzzles. If the generator cannot hit the chosen level in time, it shows the real level.
Solve your own sudoku
“Enter my own” clears the grid. Type in the givens from a newspaper or book and press “Use this puzzle”. The tool checks that the puzzle is solvable and unique, rates its difficulty and explains every step if you want.
Printing, saving and privacy
“Print” outputs only the title and the grid – no ads, no buttons. Your game is kept in your browser’s localStorage and is back after a reload. Nothing is sent to a server. New puzzles are generated on your device with the browser’s random generator (crypto.getRandomValues).
Fancy another puzzle? The Wordle solver helps with the word game.
More puzzles: make a crossword, build a word search or play hangman online.
Frequently asked questions
How do I solve a sudoku from a newspaper?
Choose “Enter my own”, type in the givens and press “Use this puzzle”. “Solution steps” then shows every step with an explanation, and “Solve” fills in the complete solution.
Does every sudoku have exactly one solution?
The puzzles generated here do – this is checked before they are shown. For puzzles you enter yourself, the tool tells you if there is no solution or more than one.
Is there a new sudoku every day?
Yes. “Daily sudoku” loads the puzzle of the day – the same for everyone, because it is calculated from the date. Mon/Tue easy, Wed/Thu/Sun medium, Fri/Sat hard. A new one appears at midnight on your device’s clock.
What do the difficulty levels mean?
They follow the hardest technique required: Easy uses singles only, Medium pointing and pairs, Hard triples and X-Wing, Expert even harder deductions.
What is a hidden single?
A number that fits in only one cell of a row, column or box – even if that cell still has other candidates.
What is the minimum number of givens?
17. There is no sudoku with 16 givens and a unique solution; this was proven by computer in 2012 (McGuire, Tugemann, Civario).
Can I print the sudoku?
Yes. “Print” outputs only the title and the grid with its current state, without buttons or ads.
Is my game saved?
Yes, locally in this browser. Reload the page and carry on. In private mode the browser deletes it when you close the window.
Sources and legal basis
As of: · Editorial policy
Related tools
- Wordle Solver – find the best next guessWordle solver: type your guesses and tap the tiles green, yellow or grey like in the game. See every word left, ranked, plus the best next guess. No spoilers.
- Online score keeperFree online score keeper and score counter for board and card games: rounds, running totals, rankings, target score and undo. Saved locally in your browser.
- Dice roller: roll d6, d20 and more onlineDice roller: roll d4 to d100 or type dice notation like 3d6+2 or 2d20kh1. Several sets at once, advantage, roll history, exact odds and a shareable link.
- Random number generatorRandom number generator: pick numbers between any two values, 1–100 or up to 1,000 at once, no repeats if you like. Powerball and EuroMillions presets.
- Play Solitaire OnlineFree Klondike solitaire in your browser: draw 1 or 3, unlimited undo, hints and a winnable daily deal. Share your time – the link deals the same cards.
- Futoshiki OnlinePlay Futoshiki online for free: number puzzles with greater-than and less-than signs in four sizes and three levels, uniquely solvable, with hints.
- Calcudoku onlinePlay Calcudoku online for free: arithmetic Sudoku from 4 × 4 to 7 × 7, one solution each, with notes, hints, error checking and a puzzle series. No sign-up.
- Maze game onlinePlay a maze game online for free: four sizes from 8 × 8 to 25 × 25, arrow keys or taps, a stopwatch, a solution path and a puzzle series. No sign-up.
- Light toggle puzzle onlinePlay the light toggle puzzle online for free: turn off every lamp on grids from 3 × 3 to 7 × 7, with hints, the minimum moves and a puzzle series.