New to Sudoku? Learn the rules on a small 4×4 grid, then solve Easy puzzles using one idea: find the only place for a digit. Add the other techniques one at a time, as the levels ask for them. This page puts the guides in that order, with a six-question warm-up to check yourself before you move up a level.
Your path, in order
- Learn the rules. The Sudoku rules page takes a few minutes and solves a 4×4 puzzle step by step. The one idea to take away: if a digit can’t go anywhere else in a row, column or box, it goes in the one place left.
- Solve your first Easy puzzle by scanning. Take the digit that appears most often, check each box for a place where only it fits, then move on to the next digit. That’s all an Easy level needs: every one can be finished this way, without notes.
- Add the cell view. When scanning runs dry, look for a cell that already sees eight different digits. It’s technique 2 in how to solve Sudoku.
- Do the warm-up below. Six questions, from a 4×4 grid up to a full puzzle, each one practising a way of finding the next digit.
- Pick up speed. The Sudoku tips page adds the scanning order, the two-out-of-three check and where to look after each move.
- When a puzzle goes wrong, read the six common mistakes. The big one is guessing.
- Move up a level when you’re ready (see below), and learn notes and the four note techniques as Medium and Hard ask for them.
Warm-up: six questions
For each one, find the digit, then open the answer. Each is a single move, and every answer has been checked by our solver.
1. Where does the 1 go in the highlighted box?
Show the answer
Row 2, column 4. The 1 in row 1 rules out the box’s top row, and the 1 in column 3 rules out row 2, column 3. One cell is left.
2. What goes in the highlighted cell?
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- Its row already has 1 and 2, and its column has 3. That leaves 4.
3. Where does the 8 go in the highlighted box?
These are rows 4 to 6 of a Medium puzzle: one band of three boxes.
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The top row of the box, row 4. The left box has its 8 in row 5 and the middle box has its 8 in row 6, so the right box’s 8 must be in row 4, and row 4 has only one empty cell there. This is the two-out-of-three check.
4. Where does the 9 go in the highlighted box?
Now a stack: columns 4 to 6 of a different Medium puzzle. The same check works down a stack, looking along columns.
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The left column of the box, in its bottom row. The top box has its 9 in column 6 and the bottom box has its 9 in column 5, so the centre box’s 9 is in column 4, and column 4 has one empty cell in the box.
5. Where does the 6 go in row 7?
The full puzzle from question 4. This time, look along a row.
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Column 8. Row 7 has five empty cells. Column 2 already has a 6, and so does the bottom-middle box, which covers columns 4, 5 and 6. That rules out four cells. Scanning the boxes wouldn’t find this 6 yet; only the row does.
6. What goes in the highlighted cell?
The same puzzle again. This time, start from the cell.
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- Its row has 1, 4 and 8. Its column adds 3, 5, 6 and 9, and its box adds 2. That’s eight digits, and 7 is the only one left. No row, column or box finds this 7 yet, so the cell view is the only way to see it.
When to move up a level
You’re ready for Medium when you can finish an Easy puzzle without guessing, you scan in a fixed order without thinking about it, and the warm-up above felt quick.
Each level needs a little more than the one before. Our levels are graded by the techniques they need:
| Level | Givens | What it needs |
|---|---|---|
| Easy | 40 | Only places, with no notes. |
| Medium | 32 | More than only places. 39 of the 50 levels need the cell view; the other 11 need a pointing or claiming step, so learn notes here. |
| Hard | 26 | A naked or hidden pair in every level, so full notes and patterns. |
Most Medium levels never need notes. When one does get stuck, write notes for one digit at a time, as in the walkthrough. Move to Hard once Medium feels routine. That’s where Snyder notes and pairs earn their keep.