About 6×6 Sudoku
6×6 Sudoku uses the same rules as the classic game on a smaller grid: every row, column and 2×3 box contains the digits 1 to 6 exactly once. With 36 squares instead of 81, a puzzle takes a few minutes, which makes it the best way to learn sudoku and a good one to teach a child.
How to play 6×6 Sudoku
- The grid has six rows, six columns and six boxes of two rows by three columns.
- Every row, column and box contains 1 to 6 exactly once.
- Start where a row, column or box is nearly full: with only six digits, the missing one is often easy to spot.
Why start here
Everything you learn on a 6×6 grid works on a 9×9 one. Scanning a row for the missing digit, checking a column before placing, using notes when two squares could each take the same digit: the techniques are identical, the grid is simply small enough to see all at once.
When easy 6×6 puzzles start to feel quick, try medium, then move to Classic Sudoku on easy.
Difficulty
Easy to Expert changes how many digits you start with, from 20 of the 36 squares on Easy to 10 on Expert. Even expert 6×6 puzzles are shorter than an easy 9×9, so the levels are about how much you have to reason, not how long it takes.
Controls
- Select a square, then use the number pad or keyboard.
- N toggles notes, Backspace erases, H gives a hint, U or Ctrl/Cmd+Z undoes.
- Progress and notes are saved for each variant separately.
Scoring
| Level | Base | Speed bonus, up to | Per mistake | Per hint |
|---|---|---|---|---|
| Easy | 1,000 | 250 | −100 | −250 |
| Medium | 2,000 | 500 | −200 | −500 |
| Hard | 3,500 | 875 | −350 | −875 |
| Expert | 5,000 | 1,250 | −500 | −1,250 |
Only fully solved puzzles are ranked. Your score is the difficulty base plus a speed bonus of at most 25% of that base. The bonus falls by 0.5 points per elapsed second, rounded to the nearest whole point, and never below zero. Each mistake deducts 10% of the base; each hint deducts 25%. A solved puzzle always earns at least 10% of its base. Undo does not refund time, mistakes or hints. Each Sudoku variant has its own leaderboard. Existing scores remain on the same boards; new solves use this formula.
