All Sudoku Variants
12×12 · Size Variant

Sudoku 12×12

Also known as Dodeka Sudoku

A 12×12 grid with 3×4 boxes using the digits 1–12.

1 2 3 4 5 6 7 8 9

An example 12×12 Sudoku: twelve symbols fill every row, column and 3×4 box (a few 1–9 shown).

12×12 Sudoku is a twelve-by-twelve grid divided into 3×4 boxes, filled with the digits 1–12. Each row, column and box must hold all twelve values once. It is one of the friendlier large formats — bigger and more absorbing than a 9×9, but built on exactly the same logic.

The rule: 1–12 in every row, column and 3×4 box

Fill the grid so no value repeats in any row, any column or any 3×4 box (three cells tall, four wide). A single box already holds a full set — below, one 3×4 box is filled with 1 through 12 to show the range you work with.

1 2 3 4 5 6 7 8 9 10 11 12

One 3×4 box holds all twelve values (1–12). The full grid has twelve such boxes.

Same logic, more to track

A 12×12 is not conceptually harder than a 9×9 — the techniques are identical — but there is more to hold in your head: twelve candidates per cell and 144 cells in all. Careful pencil-marking matters more, because a single missed elimination is easy to make and slow to find. Treat it as a longer, more meditative solve than the 9×9.

Numbers past nine

Because the digits run to 12, each cell can be two characters wide (10, 11, 12). Some puzzles instead use letters or hexadecimal-style symbols to keep every cell a single character, but the logic is unchanged — the symbols are just labels for twelve distinct values.

Solving strategy

  • Pencil-mark methodically. With twelve possible values per cell, candidate notes are essential.
  • Work box by box. Finish scanning one 3×4 box before moving on, so you don't lose your place.
  • Hunt hidden singles per value. Take one value at a time and place it wherever it is confined to a single cell.
  • Use the same techniques as 9×9. Naked pairs, hidden singles and X-Wings all scale up unchanged.

Common mistakes

  • Expecting square boxes. The boxes are 3×4 rectangles — check the borders before reasoning about a box.
  • Forgetting a value. All twelve must appear — it is easy to overlook 10, 11 or 12 while scanning.
  • Sloppy candidate marks. On a grid this size, one wrong pencil mark can derail the whole solve.
  • Rushing. The 12×12 rewards steady, careful work far more than speed.

Can I play it here?

Not yet — Sudoku 12×12 isn't one of the puzzle types SudokuStreak generates for now. But you can learn its rules above, and there's plenty here to sink your teeth into meanwhile: