Mini Sudoku

Fill the grid so every row, every column and every 2×3 box contains each digit from 1 to 6 exactly once. A wrong digit is rejected the moment you place it rather than left to poison the grid — you get three tries.

It runs entirely on your device: 0 network requests, works offline. No ads, no account, nothing to buy, and no betting, money or prizes of any kind.

1. Focus the board — click it, or press Tab until it is focused.
2. Move with the arrow keys. Given digits are bold and cannot be changed.
3. Place a digit by tapping one of the six buttons below the grid, or press Enter to place the lowest digit that does not already clash.
4. A wrong digit is refused and costs one of your three tries; it never lands on the board.
5. Fill every cell to finish.

How do you solve a Sudoku without guessing?

Ask "where can this digit go?" rather than "what goes in this cell?". Pick a digit, look at one box, and cross off every cell in it that already sees that digit in its row or column — if exactly one cell survives, you have found a placement with certainty. That single technique solves most of a 6×6, and it is the one that scales: on any size of grid, the box is usually where the constraint bites first, because it is the smallest region. Only when it stalls do you switch to asking which digits a particular cell can still take.

Is every puzzle solvable without a guess?

Yes, and it is verified rather than assumed. Cells are removed from a finished grid one at a time, and each removal is kept only if a solver confirms the puzzle still has exactly one solution — the solver counts up to two and stops. A puzzle with two answers would require a guess somewhere, and one cannot reach you.

Why 6×6 instead of the usual 9×9?

Because a 9×9 grid on a phone means pinching, mis-taps and a session that feels like work. A 6×6 with 2×3 boxes keeps every technique that matters — box elimination, row and column scanning, naked singles — in a grid that fits a 360-pixel screen at a comfortable tap size.

Why is a wrong digit refused instead of just being marked?

Because a contradiction you discover twenty moves later teaches you nothing except to start again. Refusing it immediately keeps the grid always consistent, so what you are reading is always true — and it makes the three tries a real cost rather than a scoreboard.

Does it work offline?

Yes. Once the page has loaded once, the whole game — including the generator and the solver — is on your device. There is no server involved in play at any point.

Is there any money, betting or in-app purchase in this?

None, and there never will be. No currency, nothing to buy, no hints to unlock for a fee.

Can I play it with a keyboard or a screen reader?

Both. Arrows move, Enter places, and every cell announces its row, column, value and whether it is a given. Box boundaries are drawn as borders rather than tints, so the 2×3 structure is visible without relying on colour.

Six by six with 2×3 boxes, typically nine to eleven given digits, and three wrong entries allowed. Uniqueness is checked at generation time by an exhaustive solver, not estimated.

Target 24 is the other number puzzle here — it asks for one exact value from four, where this asks for placement under constraint.

Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.