Free Sudoku, three ways.
Pick a level and start solving. New here? The rules are at the bottom whenever you want them.
Learn to actually solve
A board is easy to find. Learning why each move works is the point — that's what the rest of the site is for.
- Technique guidesAll nine methods, from naked singles to the Swordfish — with worked examples.
- Step-by-step solverPaste any grid and watch it solved, one named technique at a time.
- Daily puzzleOne a day, the same for everyone — keep your streak going.
- Puzzle archiveGraded by technique, each with its own solving notes.
- Printable sudokuSix to a page with answers — clean black-and-white.
How to play Sudoku
One rule, endless puzzles. Here's everything you need — no jargon.
What's the rule of Sudoku?
Fill the 9×9 grid so that every row, every column, and every 3×3 box contains the numbers 1 to 9 — each exactly once. That's the whole game. No maths, no adding up; it's pure logic.
Some cells start filled in. Your job is to work out the rest so nothing repeats in any row, column, or box.
How do I actually start?
Look for the cell with the fewest possibilities, not the emptiest area. Scan a row, column, or box that's already nearly full — often a number has only one place left to go.
Tap an empty cell, then tap a number to place it. Tap the number again, or use Erase, to take it back. The board flags conflicts in red the moment two of the same number share a row, column, or box.
What are notes (pencil marks) for?
When a cell could hold more than one number, jot the candidates down small. Turn on Notes, then tap the numbers that might fit. As you fill neighbouring cells, you cross off options until one answer is left.
Notes are essential on Medium and Hard — nobody holds it all in their head.
What's the difference between the levels?
Easy gives you more starting numbers and always solves with simple scanning. Medium asks you to keep notes and think a step ahead. Hard starts sparse and rewards patience and technique.
Every puzzle here has exactly one solution — you'll never need to guess blindly.
Do I ever have to guess?
No. A proper Sudoku is always solvable by logic alone. If you feel stuck, you've usually missed a cell where only one number can legally fit — slow down and re-scan the boxes.