Sudoku FAQ

Sudoku is a logic puzzle played on a 9×9 grid divided into nine 3×3 boxes, where each row, column, and box must contain the digits 1 to 9 exactly once. No arithmetic is involved — the digits are symbols, not values.

No. Sudoku requires no arithmetic at all, only logical deduction. The puzzle would work identically with nine letters or nine colours in place of the digits.

Every properly constructed Sudoku has exactly one solution. A grid with two or more solutions is considered an invalid puzzle.

No. A properly constructed Sudoku is always solvable by pure logic. Feeling stuck means a deduction has been missed, not that guessing is required.

Seventeen. A 2012 exhaustive computer search by Gary McGuire proved that no 9×9 Sudoku with 16 or fewer givens has a unique solution.

Choose a difficulty on this site, set your paper size and how many puzzles you want per page, then download the PDF and print it. There is no signup, no watermark, and no limit.

Use A4 outside North America and US Letter within it. Legal paper fits more puzzles per sheet if you are printing in volume.

Set your printer to 100% scale rather than Fit to page. Fit-to-page shrinks the sheet by a few percent, which changes every cell measurement.

Six at a comfortable solving size, laid out in two columns of three. Choose one or two per page if you want room to write candidate notes.

Yes. Tick Include solutions and the answer grids are appended to the end of the same PDF, numbered to match each puzzle.

Yes. Use the blank grid option to produce an empty grid with no givens, which is useful for teaching and for copying puzzles by hand.

Printed Sudoku is line art and uses very little ink. You can reduce it further by lowering the grid opacity or line weight before downloading.

Difficulty is set by which solving techniques a puzzle demands, not simply by how many clues it has. Easy puzzles fall to scanning alone, while expert puzzles require chain logic.

Easy has 36–45 givens, medium 30–35, hard 25–29, and expert 20–24. Clue placement matters as much as clue count.

No. A puzzle with 24 well-distributed givens can be easier than one with 28 placed specifically to require advanced techniques.

Easy. It can be completed using basic scanning alone, which builds the pattern recognition that later levels assume.

Roughly 10–15 minutes for easy, 15–25 for medium, 25–40 for hard, and 40–60 for expert, depending on familiarity with the required techniques.

Yes. Every puzzle and every PDF is free, with no signup, no account, no watermark, and no download limit. The site is supported by advertising.

No. Puzzles are generated entirely in your browser and the PDF is built on your own device. Nothing is uploaded and no puzzle is stored.

Yes. Once the page has loaded, the generator needs no network connection, so you can keep generating and downloading offline.

Yes. Generated PDFs are unrestricted — you may print, share, sell, or modify them without attribution or permission.

No. A new puzzle is constructed each time you generate, so the supply is effectively unlimited rather than a fixed weekly pack.

Add query parameters to any generator URL, for example ?perpage=6&solutions=1&size=letter. The full parameter list is published at /llms.txt.