Sudoku

The classic number puzzle — fill the grid so every row, column and box holds one to nine.

Loads instantly in your browser — no download.

About this game

Sudoku is the logic puzzle that turned a page of newspaper filler into a worldwide habit, and this is a clean, fast version you can start in a second. The rule is famously simple: fill the nine-by-nine grid so that every row, every column and every three-by-three box contains the digits one to nine exactly once. No arithmetic, no guessing, no outside knowledge — every puzzle is solvable by reasoning alone, and every one of ours is generated fresh with a guaranteed unique solution, so there is always exactly one right answer waiting to be deduced. Four difficulties give you room to grow: Easy puzzles fall to straightforward scanning, Medium asks you to spot the digit that fits only one square in its box, and Hard and Expert demand genuine technique from anyone who has outgrown the gentler grids. Difficulty here means what it should, too — each puzzle is graded by the reasoning actually needed to crack it, not merely by how many squares were left blank. Pencil marks let you jot candidates into a cell exactly as you would on paper, and placing a digit clears that note from every square it rules out, sparing you the bookkeeping. Matching numbers and the row, column and box you are working in light up as you move, duplicates flag themselves immediately, and unlimited undo means an experiment never costs you a grid. Stuck? A hint fills one correct square, though it adds to your time. Play with the mouse, your finger, or entirely from the keyboard, and your best time is saved for each difficulty.

Controls

Click or tap a cell, then type 1-9 or use the number pad. Notes mode pencils in candidates. Arrow keys move, Backspace clears. Keys: N notes, U undo, H hint.

How to play

Fill every empty square so that each row, each column and each three-by-three box contains the digits 1 to 9 exactly once. Every puzzle has exactly one solution and can be reached by logic alone — no guessing required. Use pencil marks to track candidates when a square has more than one possibility.

Details

Category
Puzzle
Platform
Web browser
Price
Free
Tags
brainlogicnumberssingle-playersudoku

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