Sudoku
Time 00:00
Difficulty –
Mistakes 0
Progress 0%
Fill the 9×9 grid without repeating a number. Four genuine levels and a daily Sudoku.
- Players
- 1
- Length
- 5–30 min
- Difficulty
- Several levels
- Genre
- Puzzle
- Modes and difficulty
- Free play · Daily
How to play
- The grid has 81 cells in 9 rows, 9 columns and 9 boxes of 3×3. Some cells start with a fixed number.
- Every row, column and box must end up with the numbers 1 to 9, each exactly once.
- Given numbers can’t be changed. You fill in the rest, in any order you like.
- Notes are helper marks: they record which numbers could go in a cell, but don’t count as an answer.
- The game ends when all 81 cells hold the right number. Your time, mistakes and hints used go into your stats.
Controls
- Pick a cell
- Click or tap; arrow keys
- Enter a number
- On-screen number pad, or 1–9 on the keyboard (numpad too)
- Pencil in candidates
- Notes button or N; Shift + number notes it without switching mode
- Erase
- Erase button, Backspace, Delete or 0
- Undo
- Undo button or Ctrl+Z
- Hint
- Hint button or H: fills the selected cell (or the first empty or wrong one)
Description
Classic 9×9 Sudoku: fill the grid so every row, every column and every 3×3 box holds the numbers 1 to 9 with no repeats. There’s no arithmetic involved; it’s pure logic, and every Vexply puzzle has exactly one solution, so it can always be solved by reasoning, never by guessing.
The four levels aren’t just about how many numbers are given: each puzzle is solved internally with the same techniques a person would use, and graded by the hardest one it needs. So an Easy puzzle will never ask you for an X-Wing, and an Expert one can’t be finished just by spotting obvious cells.
Alongside free play there’s a daily Sudoku: the same puzzle for everyone each day, in any language, with its own streak.
Classic 9×9 Sudoku with four levels graded by the techniques each board actually needs, every one with a unique solution. Notes, hints, undo and a daily Sudoku that’s the same for everyone. Your progress stays in your browser.
Modes and difficulty
Easy
Solved with obvious cells only: the one number a cell can hold, or the one place a number can go in a row, column or box. Comes with 36 to 42 givens.
Normal
Fewer givens (27 to 35) and more searching, but single candidates are still enough.
Hard
Needs intermediate techniques: locked candidates in a box and naked or hidden pairs. This is where notes become essential.
Expert
Asks for triples, X-Wing or, in the toughest ones, reasoning by cases. Can come with very few givens.
Daily
One puzzle a day, the same for everyone. Its difficulty follows the week: Easy on Mondays, Hard on Thursdays and Fridays, Expert on Saturdays. You can share your result (time, mistakes, hints) without revealing the grid.
Tips
- Start with the number that appears most on the grid: with eight of nine already placed, the missing one usually has a single spot.
- Go box by box asking “where can the 1 go?”, then the 2, and so on. It finds more cells than looking cell by cell.
- Tap a number on the grid to highlight all the matching ones: seeing where the 7s are makes it obvious where they can’t go.
- On Hard and Expert, pencil in every candidate in an area before deciding. Advanced techniques show up in the notes, not on the empty grid.
- If “Mark mistakes instantly” is off, double-check before moving on: one wrong number spreads to its whole row, column and box.
Strategy
The golden rule is: don’t guess. If you feel you have to try a number “to see what happens”, there’s almost always a deduction you haven’t spotted yet: look at the notes in the fullest box, or hunt for a pair.
When you place a correct number, the game removes it from the notes around it. Use that: after each new number, check its row, column and box, because that’s where the next solved cells appear.
FAQ
Does every puzzle have exactly one solution?
Yes. Each puzzle is checked by a solver before you see it: if it had two solutions, it’s thrown away.
How is the difficulty decided?
The puzzle is solved with human techniques in order (obvious cells, hidden singles, locked candidates, pairs, triples, X-Wing) and graded by the hardest one it needed. The number of givens is also kept within a range for each level.
Is the daily Sudoku the same in every language?
Yes: it depends only on the date. Two people playing on the same day get the same puzzle even if they use different languages.
What counts as a mistake?
Entering a number that doesn’t match the solution. With mistake marking on, the cell is struck through at once; with it off, only numbers repeated in their row, column or box are marked. Either way the mistake is counted.
Where is my progress stored?
In your browser: the game in progress, the day’s puzzle, your times per level, the daily streak and achievements. Nothing is sent to any server.
Mastery
How well you know each game: its achievements, the games you finished and your records. Worked out from your real progress in this browser.
Your performance
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