Play Sudoku Online Free

About Sudoku

Sudoku is the classic number-placement puzzle: fill a 9×9 grid so every row, every column, and every 3×3 box contains the digits 1 through 9 exactly once. Given clues start filled in; your job is to deduce the rest without guessing when you can avoid it.

This build generates a fresh puzzle each time at easy, medium, or hard. Pencil notes, conflict highlighting, hints, a timer, and local best times are built in. Progress stays in your browser, so you can leave a half-finished grid and come back later.

How to play Sudoku

Select an empty cell, enter a digit, and keep every house unique until the board is complete.

1. Tap or click a cell that is not a given clue, then enter a digit from 1 to 9 with the pad or keyboard.
2. Turn on Notes to place candidate marks in a cell; placing a final digit clears that cell’s notes and removes the digit from peers.
3. Conflicts light up when a digit repeats in a row, column, or 3×3 box — fix those before chasing speed.
4. Use Hint to reveal one correct empty cell when you are stuck; the timer keeps running until the puzzle is solved.
5. Choose Easy, Medium, or Hard for a new generated puzzle; your best finish time for that difficulty is stored locally.

Sudoku strategy tips

• Scan for singles first: a digit that appears only once as a candidate in a house is safe to place.
• Keep pencil notes tidy — erase a candidate as soon as a peer forces it out, or the board becomes noise.
• Work one box or one digit at a time when the whole grid feels overwhelming.
• If two cells in a house share the same two candidates, those digits are locked there — remove them elsewhere.
• Use Hint sparingly for learning, not as a substitute for scanning; racing your own best time rewards clean technique.

Sudoku FAQ

Is every puzzle here uniquely solvable?

Yes. Puzzles are generated with a single solution. Conflict highlighting marks illegal repeats while you work; a finished board matches that unique solution.

What do Easy, Medium, and Hard change?

They change how many clues remain and how deep the solving path goes. Easy leaves more givens; Hard removes more and expects longer chains of deduction.

Do I need an account to save progress?

No. The current puzzle, notes, timer, and best times for each difficulty stay in this browser’s local storage until you clear site data.

Does using a hint stop the timer?

No. The timer runs until the grid is complete. Hints fill a correct empty cell so you can continue, and best times still record the full elapsed time.

Games like Sudoku

2048Another solo number puzzle — merge tiles instead of placing digits.Tic-Tac-ToeQuick grid logic when you want a short two-player break.GomokuCalm board focus with lines instead of houses.