Sudoku FAQ

Quick answers about the puzzle and the tools on this site. Follow the links for a lesson, a format choice or a fuller explanation.

Rules and learning

Do I need arithmetic to play?

Classic Sudoku uses digits as symbols. Fill each row, column and 3-by-3 box with 1–9 once each; no sums are required. See the rules. Variants such as Killer Sudoku add their own constraints.

Where should a complete beginner start?

Choose a format on the beginner starting page, or go directly to the interactive course. You can practise a few moves before attempting a complete puzzle.

What are pencil marks?

They are small notes for candidate digits in an unsolved cell. They record possibilities rather than confirmed entries. The beginner checklist explains when to check and update them.

What if I cannot find a move?

Check recent entries and notes, then use the stuck guide. An unexplained placement is harder to retrace than a candidate left as a note.

Playing and difficulty

Where is today's puzzle?

Open daily Sudoku and use its difficulty selector. Check the date displayed on the board.

How do I choose a level?

Start with a level that lets you explain some moves, then adjust to suit your session. Read the difficulty guide; labels from different publishers are not directly interchangeable.

How quickly should I finish?

There is no universal target. The solving-time guide explains how to compare attempts while accounting for help, interruptions and familiar puzzles.

Printing and email

Where do I download a puzzle?

Use the printable chooser to select a format, difficulty and A4 or US Letter paper. Preview the selected file before printing.

Which downloads include solutions?

The standard weekly pack has a separate solution page. Daily sheets and the four- and six-per-page formats omit answers. Match the puzzle date and difficulty when checking a solution.

Can I print just one puzzle?

Choose the daily single-puzzle sheet. Selecting one page from a multi-grid pack prints every grid on that page.

Must I subscribe to download?

No. Downloads are available without an email subscription. Optional puzzle emails are offered separately through the weekly page.

Are there empty grids or reference sheets?

Yes: blank grids, the rules sheet and the strategy sheet. Puzzle packs are generated by the site.

For more solving help, browse Sudoku tips.