Blank Sudoku grids
Empty 9×9 grids with squares big enough to write candidates in, for copying a puzzle across or composing one yourself.
The grids
Grid 1 Grid 2 Grid 3 Grid 4 Grid 5 Grid 6
Why copy a puzzle out at all
To have a second attempt. A hard puzzle worked in pen is finished the first time it goes wrong, and copying the clues onto a fresh grid costs two minutes against restarting an evening.
To make it annotatable. Newspaper Sudoku is printed small — often under 5 mm a square — and the harder levels need candidates written in. Copying onto a large grid is the difference between finishing and abandoning it.
And to work from a screen without a screen. A puzzle on a phone is a puzzle you cannot annotate; nine numbers copied onto paper makes it a real one.
Setting a puzzle by hand
It is harder than it looks, and the trap is the one this whole site is built around: a grid that looks like a Sudoku will usually have more than one solution.
The reliable method is to work backwards. Fill a complete valid grid first, then remove clues one at a time, checking after each removal that only one solution remains. That check is not something to do by eye — paste the grid into the solver, which answers it exactly.
Symmetry is conventional rather than required. Most printed Sudoku is symmetric about the centre because it looks composed, and it costs a few extra clues to achieve.
Sizes on the page
Six grids to a page is the default and gives squares of about 13 mm, which is comfortable for pencil marks. Four to a page gives about 17 mm, which is generous.
One to a page is for teaching, or for a puzzle you intend to work at over several sittings. At that size a grid takes most of an A4 sheet and there is room to write reasoning in the margin.
The box borders print heavier than the square borders. That sounds cosmetic and it is not: without it the 3×3 structure disappears at a glance and the grid becomes much harder to scan.
Common questions
What size should a printed Sudoku grid be?
About 13 mm a square is comfortable for pencil marks, which is six grids to an A4 page. Newspaper Sudoku is often under 5 mm, which is why it is hard to annotate.
How do I make my own Sudoku puzzle?
Fill a complete valid grid, then remove clues one at a time, checking after each removal that exactly one solution remains. Skipping that check is how a puzzle ends up with two solutions.
Why are the box borders darker?
Because without them the 3×3 structure vanishes at a glance and the grid becomes much slower to scan. It reads as decoration and it is doing real work.