How do you play Suguru?

The grid is split into outlined regions of one to five squares. A region of N squares holds each of the digits 1 to N exactly once, so a three-square region holds 1, 2 and 3, and a one-square region holds a 1. Two equal digits may never touch, along an edge or at a corner, whether they sit in the same region or in neighboring ones. The board here counts as solved only when every square is filled and no rule is broken.

Does every Suguru puzzle here have exactly one solution?

Yes. Each puzzle starts as a region map drawn from its seed, which a seeded search fills with a complete valid grid. Digits are then removed one square at a time, and a removal is kept only while three deductions still finish the grid: a square with one digit left takes it; a digit with one square left in its region goes there; and when every square of a region that can still take a digit touches the same outside square, that square cannot take it. Each deduction only rules out digits that no solution could have there, so finishing the grid with them proves the solution is the only one and that nobody has to guess. Many region maps cannot be filled at all, since every 2 x 2 block needs four different digits and small regions packed together cannot supply them, and a map the seeded search cannot fill within its step limit counts the same way; those are dropped and the next map from the same seed is tried, up to 150. If none pass, the page says so and names the next seed to try.

How do pencil marks work?

Press Pencil under the grid, or P on a keyboard, and the digits add or remove small pencil marks in the selected square instead of filling it. Press it again to go back to digits. Pencil marks go only in empty squares and only up to the size of the square's region, so a three-square region takes marks 1 to 3. Typing a digit into a square clears its pencil marks. Pencil marks are saved with your progress, and Undo takes them back like any other move.

What does the Hint button do?

It checks your board in order. First it names two touching squares that hold the same digit, then a digit repeated in one region. Next it names a digit you typed that breaks no rule but is not part of the only solution. When everything on the board is right, it names a square that can only hold one digit and gives the reason for each other digit (already in the region, touching an equal digit, or needed by a region whose remaining squares all touch this one), or a digit that has only one square left in its region. If neither exists, it shows one digit of the solution. It outlines the squares it is about and, when it names one square, moves the cursor there, but it never types a digit for you, and each hint adds one to the hint count in the check pane.

How do I play on a phone or with a keyboard?

Tap a square to select it, then press a digit on the pad under the grid. The pad also has arrow buttons to move between squares, Erase, and Pencil, all at a size that is easy to tap even when a 10 x 10 grid makes the squares small. On a keyboard, the arrow keys, Home and End move around the grid, 1 to 5 enter a digit, Delete, Backspace or 0 erases, P switches pencil marks on and off, Ctrl+Z or Cmd+Z undoes, and Ctrl+Y or Ctrl+Shift+Z redoes.

Can I print a Suguru puzzle?

Yes. Print sends a sheet with the grid, heavy lines around each region and the given digits, headed with its size and seed and with the rules underneath. Tick the box to add the answer on a second page. Squares print at 20 mm on grids up to 7 x 7 and shrink to 15 mm on a 10 x 10, so every grid fits within 150 mm. Copy puts the same board on the clipboard as text, with your digits and the region map beside it.

What is the seed, and can I play the same puzzle again?

The seed is a whole number from 1 to 999999. The generator draws its random numbers from a fixed formula seeded by the grid size and the seed, so the same pair gives the same puzzle on any device. The size and seed of the puzzle on the board are shown above it and in the Seed box. To open a puzzle again, choose its size, type its seed and press Play seed. New puzzle, or choosing another grid size, starts a random seed.

Is my progress saved?

Yes, in this browser only. The puzzle on the board, your digits, your pencil marks and its hint count are kept, along with up to 9 earlier puzzles you left with a digit, a pencil mark or a hint used, so a reload or a later visit opens where you left off. Resume reopens an unfinished puzzle as you left it, and Play again reopens a solved one on an empty grid. Undo reaches back through up to 400 moves made since the puzzle was opened in this visit. Nothing is uploaded, and the Start over button at the top of the page forgets all of it. If the browser refuses storage, the header of the check pane says the puzzle is not being saved, and it still plays.

Suguru Puzzles

Fill each outlined region of N squares with the digits 1 to N so that no two equal digits touch, not even diagonally. Every puzzle here is generated on this page, from 5 x 5 to 10 x 10 with regions of one to five squares, and offered only after a solver has proved it has exactly one solution and that logic alone reaches it, with no guessing. Tap a square and type a digit, or use the pad under the grid, which also moves between squares at phone size; Pencil switches the digits to pencil marks. A square turns red the moment it touches an equal digit or repeats one in its region, and the check pane says which rule broke. Hint names the next square you can work out and the reason, without typing it for you. Undo and redo step back and forth through your moves, your progress and recent puzzles stay in this browser, the same size and seed make the same puzzle on any device, and any puzzle prints, with its answer on a second page if you want it.

puzzleno puzzle yet

Setting up the board

Your saved puzzle, or a new one, appears here in a moment.

checksaved once you play

rules: Each outlined region of N squares holds the digits 1 to N, each once. Equal digits never touch, not even diagonally, inside a region or across its edge.
hints: none yet
keys: arrows move, 1 to 5 enter, P pencil, Delete erases

Setting up the board.

Grid

Seed

Filled

none yet

Regions done

none yet

Clashes

none yet

Print the answer on a second page

Tap a square, or move to it with the arrow keys, then type a digit or press one on the pad under the grid. Pencil (or P) switches the digits to pencil marks and back. Delete, Backspace or 0 erases, and Ctrl+Z or Cmd+Z undoes. A square turns red the moment it touches an equal digit, including diagonally, or repeats a digit in its region. Hint names a clash or a repeat first, then a digit that is not part of the only solution, then the next square you can work out and why. The size and seed on the board make the same puzzle again anywhere, and your progress stays in this browser.

Your recent puzzles

No earlier puzzles yet. Each puzzle you leave with a digit, a pencil mark or a hint used is kept here with its seed and your progress, up to 9, so you can go back to it.

How the rules are checked

A three-cell regionregion E: c3, d2, d3
holds exactly 1, 2 and 3; here 1, 3, 2, so it is done
Equal digits diagonally adjacentc4 = 2 in region B, d3 = 2 in region E
invalid across the region boundary; both squares are marked
A size-one regione1, region J
is 1, and none of its 5 neighbors can also be 1

Accuracy. Each region of N squares holds 1 to N exactly once, and equal digits never touch, diagonally included, inside a region or across its edge; a clash is marked as soon as it is typed. Every puzzle is original, generated on this page, and offered only after a solver working within a set step limit has proved it has exactly one solution, reachable without guessing. There is no difficulty rating, because none is measured.

Common questions

How do you play Suguru?: The grid is split into outlined regions of one to five squares. A region of N squares holds each of the digits 1 to N exactly once, so a three-square region holds 1, 2 and 3, and a one-square region holds a 1. Two equal digits may never touch, along an edge or at a corner, whether they sit in the same region or in neighboring ones. The board here counts as solved only when every square is filled and no rule is broken.
Does every Suguru puzzle here have exactly one solution?: Yes. Each puzzle starts as a region map drawn from its seed, which a seeded search fills with a complete valid grid. Digits are then removed one square at a time, and a removal is kept only while three deductions still finish the grid: a square with one digit left takes it; a digit with one square left in its region goes there; and when every square of a region that can still take a digit touches the same outside square, that square cannot take it. Each deduction only rules out digits that no solution could have there, so finishing the grid with them proves the solution is the only one and that nobody has to guess. Many region maps cannot be filled at all, since every 2 x 2 block needs four different digits and small regions packed together cannot supply them, and a map the seeded search cannot fill within its step limit counts the same way; those are dropped and the next map from the same seed is tried, up to 150. If none pass, the page says so and names the next seed to try.
How do pencil marks work?: Press Pencil under the grid, or P on a keyboard, and the digits add or remove small pencil marks in the selected square instead of filling it. Press it again to go back to digits. Pencil marks go only in empty squares and only up to the size of the square's region, so a three-square region takes marks 1 to 3. Typing a digit into a square clears its pencil marks. Pencil marks are saved with your progress, and Undo takes them back like any other move.
What does the Hint button do?: It checks your board in order. First it names two touching squares that hold the same digit, then a digit repeated in one region. Next it names a digit you typed that breaks no rule but is not part of the only solution. When everything on the board is right, it names a square that can only hold one digit and gives the reason for each other digit (already in the region, touching an equal digit, or needed by a region whose remaining squares all touch this one), or a digit that has only one square left in its region. If neither exists, it shows one digit of the solution. It outlines the squares it is about and, when it names one square, moves the cursor there, but it never types a digit for you, and each hint adds one to the hint count in the check pane.
How do I play on a phone or with a keyboard?: Tap a square to select it, then press a digit on the pad under the grid. The pad also has arrow buttons to move between squares, Erase, and Pencil, all at a size that is easy to tap even when a 10 x 10 grid makes the squares small. On a keyboard, the arrow keys, Home and End move around the grid, 1 to 5 enter a digit, Delete, Backspace or 0 erases, P switches pencil marks on and off, Ctrl+Z or Cmd+Z undoes, and Ctrl+Y or Ctrl+Shift+Z redoes.
Can I print a Suguru puzzle?: Yes. Print sends a sheet with the grid, heavy lines around each region and the given digits, headed with its size and seed and with the rules underneath. Tick the box to add the answer on a second page. Squares print at 20 mm on grids up to 7 x 7 and shrink to 15 mm on a 10 x 10, so every grid fits within 150 mm. Copy puts the same board on the clipboard as text, with your digits and the region map beside it.
What is the seed, and can I play the same puzzle again?: The seed is a whole number from 1 to 999999. The generator draws its random numbers from a fixed formula seeded by the grid size and the seed, so the same pair gives the same puzzle on any device. The size and seed of the puzzle on the board are shown above it and in the Seed box. To open a puzzle again, choose its size, type its seed and press Play seed. New puzzle, or choosing another grid size, starts a random seed.
Is my progress saved?: Yes, in this browser only. The puzzle on the board, your digits, your pencil marks and its hint count are kept, along with up to 9 earlier puzzles you left with a digit, a pencil mark or a hint used, so a reload or a later visit opens where you left off. Resume reopens an unfinished puzzle as you left it, and Play again reopens a solved one on an empty grid. Undo reaches back through up to 400 moves made since the puzzle was opened in this visit. Nothing is uploaded, and the Start over button at the top of the page forgets all of it. If the browser refuses storage, the header of the check pane says the puzzle is not being saved, and it still plays.

Each region of N squares holds 1 to N exactly once, and equal digits never touch, diagonally included, inside a region or across its edge; a clash is marked as soon as it is typed. Every puzzle is original, generated on this page, and offered only after a solver working within a set step limit has proved it has exactly one solution, reachable without guessing. There is no difficulty rating, because none is measured.