About Sudoku
Sudoku is the classic 9×9 logic puzzle, free in your browser. Fill every row, every column, and every 3×3 box with the numbers 1 through 9 — no repeats. Pick from four difficulties, Easy to Expert, and every puzzle is generated with exactly one solution, so pure logic always gets you there. Pencil notes, conflict highlighting, hints, and a timer are built in. No signup, no download, and your game saves automatically so you can pick it back up later.
How to Play
- Pick a difficulty: Easy, Medium, Hard, or Expert. Harder puzzles start with fewer given numbers.
- Tap a cell, then tap a number on the pad (or press 1–9 on your keyboard) to fill it.
- Every row, column, and 3×3 box must contain 1 through 9 exactly once.
- Toggle notes mode to pencil in small candidate numbers while you work out a cell.
- Wrong entries flash red and count as mistakes. Use undo to step back, or a hint (3 per game) when you're stuck.
- Fill the board correctly to win. Your time is saved as a best per difficulty.
Tips & Strategy
- Start with scanning: pick a number that appears often and check which cells in each box can still hold it.
- Hunt for singles first — cells where only one number can go, or numbers with only one possible cell in a row, column, or box.
- Use pencil notes on harder puzzles. Seeing every candidate is how naked pairs and other patterns jump out.
- A naked pair — two cells in the same unit sharing the same two candidates — lets you erase those numbers from every other cell in that unit.
- Never guess. Every puzzle here has one solution, so there is always a logical next step. If you're stuck, re-scan; something changed since your last pass.
The Sudoku Family
The modern puzzle was created by American architect Howard Garns in 1979 under the name Number Place, then exploded after the Japanese publisher Nikoli refined it as Sudoku — roughly "single numbers" — in the 1980s, and The Times of London kicked off the global boom in 2004. Today the cluster spans Sudoku.com, Web Sudoku, NYT Sudoku, killer sudoku, daily sudoku challenges, and printable sudoku books. Sudoku on FunClicker is the clean browser version: four difficulties, pencil notes, unlimited free puzzles with a guaranteed unique solution, and no account — plus easy sudoku that's genuinely friendly for kids and beginners.
FAQ
What are the rules of sudoku?
Fill the 9×9 grid so every row, every column, and every 3×3 box contains the numbers 1 through 9 exactly once. The starting numbers are fixed, and a proper puzzle has exactly one solution reachable by logic alone.
What is the trick to solving sudoku?
Scan for singles first: cells with only one possible number, and numbers with only one possible cell in a unit. When those run out, pencil in candidates and look for patterns like naked pairs. Work in passes — every number you place unlocks new deductions.
Is sudoku good for your brain?
Yes. Sudoku exercises working memory, concentration, and logical reasoning. Studies of adults who do number puzzles regularly link the habit to sharper short-term memory and problem-solving performance, and it's a popular daily exercise for keeping the mind active at any age.
Does sudoku involve math?
No arithmetic at all. The numbers are just nine distinct symbols — the puzzle would work identically with letters or shapes. Sudoku is a pure logic and pattern game, which is why it works for any language and any age.
Can a sudoku have two solutions?
A proper sudoku can't — one unique solution is part of the definition, and it's what makes the puzzle solvable by logic instead of guessing. Every puzzle generated here is checked for a unique solution before you see it.
What is the minimum number of clues a sudoku can have?
17. Mathematicians proved in 2012 that no 16-clue sudoku with a unique solution exists, after a computer search covered every possibility. Most puzzles you'll play have between 22 and 40 clues depending on difficulty.
How long should a sudoku take?
Casual players finish an easy puzzle in 5 to 10 minutes and a medium in 10 to 20. Hard and expert puzzles can take 20 to 45 minutes or more. Speed solvers clear easy grids in under 2 minutes — the timer here tracks your best for each difficulty.
What do the sudoku difficulty levels mean?
Difficulty mostly reflects how many numbers you start with and how advanced the required techniques get. Easy puzzles here start with around 40 clues and need only singles; Expert starts with around 24 and expects candidate work like naked pairs.
What does sudoku mean?
It's short for a Japanese phrase — sūji wa dokushin ni kagiru — meaning "the digits are limited to single occurrences." The abbreviated name Sudoku was popularized by the Japanese puzzle publisher Nikoli in the 1980s.
Is Sudoku free on FunClicker?
Yes. Unlimited puzzles at all four difficulties, completely free. No signup, no download, no daily limit. Your progress saves in your browser, so you can close the tab and finish a puzzle later.
