Welcome to PlaySudoku.click, a free online Sudoku puzzle game with no registration required. Choose from four grid sizes — 4×4, 6×6, 9×9 and 16×16 — and three difficulty levels: easy, medium and hard. A new puzzle is generated every time, so there is always a fresh challenge waiting.
Sudoku is a logic-based number placement puzzle. The goal is simple: fill every row, column and box with each digit exactly once. No arithmetic is involved — only reasoning, pattern recognition and careful deduction. It is one of the most widely played puzzles in the world, and for good reason. A single puzzle can take anywhere from five minutes to over an hour depending on the difficulty and grid size you choose.
Playing Sudoku regularly is widely associated with improved concentration, sharper logical thinking and a satisfying sense of calm focus. Many players use it as a daily mental exercise — a quiet ritual that requires just enough attention to clear the mind of everything else. Online Sudoku offers the added convenience of instant puzzle generation, conflict checking and the ability to start a new puzzle at any time.
This site offers easy Sudoku for beginners, medium Sudoku for the everyday player, and hard Sudoku for those who want a genuine challenge. The 16×16 grid, using digits 1–9 and letters A–G, is available for dedicated enthusiasts. All puzzles are randomly generated, guaranteed to have exactly one valid solution, and can be printed directly from your browser.
Every puzzle begins the same way: determine which number belongs in which cell. The most reliable first step is scanning — going through each row, column and box to find any cell where only a single digit can legally appear. A cell with just one possibility is called a naked single, and grids at every difficulty level offer several of them at the outset. Work row by row, then column by column, then box by box. You will often place a dozen digits before needing to reason more carefully.
The second essential technique is the hidden single. Rather than asking which numbers fit in a particular cell, ask which cell within a row, column or box can hold a particular digit. If only one cell in a row can legally contain the digit 5, then 5 goes there — regardless of how many other possibilities that cell may appear to have. Naked singles and hidden singles together are sufficient to solve the vast majority of easy and medium puzzles without any guessing whatsoever.
The 4×4 grid is ideal for younger players or anyone wanting a very quick solve — it uses only the digits 1 through 4 across four rows, four columns and four small 2×2 boxes. The 6×6 grid steps the challenge up with a 2×3 box structure and is well-suited to players who want a meaningful puzzle without the full time investment of a nine-by-nine. The classic 9×9, the format found in newspapers, puzzle books and international competitions, remains the best balance of depth and accessibility. The 16×16 grid uses digits 1 through 9 alongside letters A through G, covering 256 cells in total. It is a serious undertaking, most rewarding in a long and uninterrupted session.
Every puzzle on this site is generated fresh in your browser on each visit — no two games are the same. Conflicts are highlighted automatically as you play: any digit that clashes with another in the same row, column or box is shown in red. The Check button confirms whether your completed grid is correct. Reset Cell clears the selected square while leaving everything else in place. Clear Mine removes all of your own entries without disturbing the given clues. Reveal Solution fills the board with the correct answer — most useful when you want to trace back and understand exactly where a chain of reasoning went wrong. Every puzzle has exactly one valid solution, reachable by logic alone.
The game runs entirely in the browser with no app required, and works equally well on phones, tablets and desktop computers. On a keyboard, number keys enter digits directly into the selected cell, and the arrow keys navigate between cells without lifting your hands. The Delete or Backspace key erases a user-entered digit. The puzzles can also be printed from any device: the Print Puzzle button activates a clean, ink-friendly layout that strips away all interface elements and presents the board at a size suited to standard paper — a useful option for those who prefer to solve with a pencil.