🔢 Sudoku LOGIC • 9x9

Fill every row, column, and 3×3 box with 1-9. Tap a cell, use the number pad or keyboard. Toggle notes for pencil marks, hints reveal a cell. Auto-checks completion, mistakes turn red. Best times per difficulty saved locally.

Time

00:00

Mistakes

Clues

Best

—

Click cell → number pad or keys 1-9 • Arrows move • Del/0 erase • N notes • H hint • Ctrl+Z undo

🎮 Controls

Clickselect cell

1-9place number / toggle note

Arrows0 / DelNH

Same row/col/boxauto-highlighted

Mistakes turn red. Same values glow. Given clues are locked. Timer stops on win. Best time saved as playroom-best-sudoku.

🏆 Best Times

Diff	Best	Status
Easy	—	—
Medium	—	—
Hard	—	—

💡 Strategy

Look for row/col/box with only one possible spot for a number.
Use notes to track candidates. Toggle with N.
Hard puzzles have 26 clues — need chain reasoning.
Select a number to highlight all matching values.

About Sudoku

📁 Puzzle 🎯 Difficulty: Medium ⏱️ Duration: 5–15 min ⚡ Instant Play (No Download) 📱 Desktop & Mobile

📖 How to Play & Objective

Fill the 9x9 grid with numbers 1 through 9. Every row, column, and 3x3 block must contain every digit exactly once with no repetitions or guessing required.

Each row must contain digits 1–9 without duplicates.
Each column must contain digits 1–9 without duplicates.
Each of the nine 3x3 subgrids must contain digits 1–9 without duplicates.
Use pencil marks to track candidate numbers for challenging cells.

🎮 Controls Guide

💻 Desktop:

Arrow keys to select cell ; numbers 1–9 to enter digit ; Backspace/Delete to clear

📱 Mobile:

Tap cell to select, then tap keypad digit below board

💡 Tips & Strategy

Start by scanning for numbers that already appear frequently across multiple rows and columns.
Use the "Sole Candidate" technique: if only one number can legally fit in a cell, it must be that number.
Use pencil notes on cells with only 2 candidate numbers to spot naked pairs.