How the test works
- The 9×9 grid is split into 3×3 boxes. Some squares already have numbers.
- Fill every empty square so each row, each column and each box has the numbers 1 to 9 exactly once.
- Pick a square, then a number (or type it). A number that clashes with another in the same row, column or box turns red. Turn on Notes to pencil in options.
- Stuck? A hint fills in a square but adds 20 seconds. Your score is your time in seconds, hints included. Lower is better.
What it measures
Sudoku is a logic puzzle: no maths, only reasoning about where each number can go. It trains working memory, concentration and step-by-step problem solving. Every puzzle here is new, has exactly one answer and can be solved by logic alone, without guessing.
A new puzzle every game
Every 9×9 puzzle here is generated when you start, so you never get the same one twice. Each one has a single solution and can be finished with logic alone: at every step at least one square can be worked out from the numbers already on the board. If you get stuck, a hint shows you one of those squares.
What is a good score?
| Score | Faster than about |
|---|---|
| 211 s | 99% of people (top 1%) |
| 337 s | 90% of people (top 10%) |
| 443 s | 75% of people |
| 600 s | 50% of people (average) |
| 813 s | 25% of people |
Estimated from typical scores for this kind of test.
Tips to improve
- Look for a square that only one number can fill, or a number that fits in only one square of a row, column or box.
- Start with the rows, columns and boxes that are nearly full.
- Use Notes for squares with two or three options, and clear them as you go.
- Need a break? Pause stops the clock and hides the board until you come back.
- New to Sudoku? Try the 4×4 or 6×6 board first.
Frequently asked questions
What is a good time for a 9×9 Sudoku?
About 10 minutes is typical for these puzzles. Under 5½ minutes puts you in roughly the top 10%, and under 4 minutes is in the top 2-3%. Each hint adds 20 seconds.
Which size should I play?
4×4 suits young children and first-timers, 6×6 is a good next step, and 9×9 is the classic Sudoku.
Do I need to be good at maths for Sudoku?
No. The numbers are just symbols; you could play with letters or colours. Sudoku is about logic: working out which number can go where.