SudokuBoku
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Find your kind of sudoku.

Classic grids, smaller puzzles and new rules to explore. Choose a game and make your next move.

Play classic Daily puzzle
Explore the collection
9×9 TOP-LEFT CORNER 19762855 5 5 5

One place for this digit

The two given 5s rule out the other spaces in the outlined box.

Hidden single
5 has one home in this box.

Choose your classic level

Levels follow the techniques needed to solve a puzzle.

How we grade
The collection · 15 games

Choose a grid size or try a new rule. The previews show how each game works.

Classic rules, three sizes

The familiar row, column and box rules, on a grid that suits you.

3 games
  • ONE 3×3 BOX 18349257 6 CHECK THEDIGITS 1 2 3 4 5 6 7 8 9 All nine Which digit is missing? One of each.

    Classic 9×9

    Nine digits, no repeats — across every row, column and box.

  • ONE 3×2 BOX 13456 2 1 2 3 4 5 6 SIX DIGITS 1–6 in everyrow, columnand box Box complete Which of 1–6 is missing? Six digits. A smaller solve.

    Mini 6×6

    Fill a 6×6 grid with 1–6, using boxes three cells wide and two tall.

  • THE WHOLE 4×4 GRID 13434122344123 21 FOUR DIGITS 1–4 Once in eachrow, columnand 2×2 box Row 1: 2 Row 3: 1 Fill the missing digits. A small grid to get started.

    4×4

    Get started with sixteen cells, four small boxes and just the digits 1–4.

Follow the markings

Use paths, totals, signs and shapes to narrow down the digits.

6 games
  • ONE 3×3 BOX 1 8 3 4 6 9 2 5 7 FROM BULBTO TIP Bulb Rise Tip Start at the bulb 2 < 4 < 6 < 8

    Thermo

    Digits rise along each thermometer, from bulb to tip.

  • ONE TWO-CELL CAGE 17 8 9 8 9 Either order ONLY POSSIBLE PAIR 8 + 9 = 17 ADD UPTHE CAGE 2 cells No repeats One pair Two cells. Total 17.

    Killer

    Find the digits from each cage’s total, with no repeats inside it.

  • ONE 3×3 BOX 397 2 4 6 FOLLOWTHE SUM Path Add Circle Add the path digits 2 + 4 = 6

    Arrow

    Add the digits along an arrow to find the number in its circle.

  • THREE NEIGHBOURS 258 One valid example Smaller Larger Read each comparison Follow the signs

    Greater Than

    Compare neighbouring digits: each sign points to the smaller number.

  • RULE EXAMPLES 3 6 7 Filled: double 3 × 2 = 6 Hollow: one apart 6 + 1 = 7 SEPARATE PAIR 3 8 No dot Neither double nor one apart

    Kropki

    Filled dots mean double, hollow dots mean one apart, and no dot means neither.

  • CANDIDATE EXAMPLES 4 5 Circle: odd 1 3 5 7 9 7 6 Square: even 2 4 6 8 Unmarked: odd or even

    Odd-Even

    Circles allow odd digits, squares allow even digits, and unmarked cells allow either.

Look across the grid

Explore new regions, extra rules, hidden ships and overlapping grids.

6 games
  • ONE NINE-CELL REGION 28754193 6 CHECK THEDIGITS 1 2 3 4 5 6 7 8 9 All nine Which digit completes the shape? One of each. A different shape.

    Jigsaw

    Place 1–9 once in every row, column and irregular region.

  • WHOLE 9×9 GRID 5 5 1–9 ON EACHDIAGONAL Centre cell R5C5 · NOTE 5 Candidate 5 5 ruled out Both diagonals count.

    X-Sudoku

    Add two more lines to check: both diagonals must contain 1–9 without repeats.

  • TOP-LEFT CORNER 9 9 FOUR EXTRAWINDOWS 1–9 in everyshaded window R2C2 · NOTE 9 Candidate 9 9 ruled out One window. No repeated 9.

    Hyper

    Use 1–9 once in four extra windows as well as the usual boxes.

  • 9×9 GRID FRAGMENT Move guide 5 5 KNIGHT’SMOVE 2 across 1 down R4C5 · NOTE 5 Candidate 5 5 ruled out A knight’s move forbids a match.

    Anti-Knight

    A chess knight’s move links cells that must hold different digits.

  • 9×9 GRID FRAGMENT 5 5 4 4 2 2 6 6 FLEET CLUE 5 4 2 6 Read in order Ship matched Water Clear on all sides,corners included. A matching placement

    Battleship

    Match ordered digit clues to hidden ships while you solve the sudoku.

  • FIVE 9×9 GRIDS ONE BOXTWO GRIDS Top-left Centre Same ninesquares. Five grids. Shared corners.

    Samurai

    Solve five 9×9 grids connected by four shared corner boxes.

Find your next puzzle

A familiar grid.
A different way to think.

The best reason to try a variant is curiosity. You can keep the Sudoku skills you already have and give yourself something new to notice: a changed region, a diagonal, or a sum connecting a few squares.

What would you like to explore?

TryWhat changesLook for
X-Sudoku Two diagonals also contain 1–9. A familiar scan in a new direction.
Jigsaw Irregular regions replace the boxes. Where a shape meets a row or column.
Killer Coloured cages carry totals. Which combinations fit the sum.

These are different rules to explore; each game has its own level choices.

A new shape changes where you look

In classic Sudoku, you learn to recognise the nine squares of a box almost without thinking. Jigsaw makes you follow an outline instead. Both regions below contain every digit once, but the irregular one crosses four columns, giving you different places to check against the rest of the grid.

Classic One 3×3 box

628754193

Jigsaw One nine-cell region

628754193
Same digits, different boundaries. Each outlined region contains 1–9 once. Rows and columns still follow that rule.

A sum gives you another way in

A Killer cage tells you how much its cells add up to, with no repeated digit inside. Three cells totalling 6 must contain 1, 2 and 3. That is useful information before you have placed anything: all six other digits can be ruled out of those cells.

One three-cell cage

6 123 123 123

1 + 2 + 3 = 6

One possible set. Six possible orders.

The total identifies the digits; the rest of the grid decides where they belong.

Arrow uses addition too, but its total is a digit you solve for in a circle. Thermo replaces addition with order: values increase along the path. Choose the kind of clue you enjoy reading, then pick a level within that game.

Explore Arrow Explore Thermo

Care that shapes the solve

A difficulty label should tell you something about the thinking ahead.

  • Check the answer

    A uniqueness check searches for a second valid completion. A puzzle passes when there is only one.

  • Assess the moves

    The grader tries known solving techniques and records the most demanding move it needs.

  • Show the reason

    A technique hint highlights the relevant squares and explains the deduction you can make.

A check on the labels

10,000 classic grids, graded again

This imported batch arrived as Evil or Extreme. Our grader put 1,915 of those puzzles in Hard or Expert.

Extreme
6,733 · 67.3%
Evil
1,352 · 13.5%
Hard or Expert
1,915 · 19.2%
Results from the imported classic bank. Here, Extreme means our built-in technique ladder could not finish the solve.

When the hint system runs out of deductions, it can offer a clearly labelled digit reveal. The full process guide explains the checks and their limits.

How we make and test the puzzles

Take a few puzzles to paper

Choose your grids and page layout, then print a pack with an answer key for later.

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