Plainoku · A quiet puzzle break
Queens-style cat placement, not number sudoku. One cat per row, column and color region.
Use arrow keys to move between squares. Enter or Space places a cat, or marks a square in Mark mode. Tab leaves the board.
Tap to place a kitty. Use Mark to rule a square out.
No ads. No pop-ups. No sign-up.
Plainoku is a quiet browser game for people who enjoy finding a place for every cat. Cat Sudoku is the everyday name we use for this experience, but the rules are specifically Queens-style placement logic. You place cats rather than numbers. Each row, column and colored region needs exactly one cat, and no two cats may touch, including at a corner. There are no digits from one to nine and no fixed three-by-three boxes to fill.
You can play immediately on the board above. There is no account, installation or payment step, and Plainoku does not load advertising or tracking code. Choose a size that suits your screen and available time. The five tier names describe board size, not a measured rating of logical difficulty. A larger grid offers more positions to consider, while the particular region arrangement determines which deductions are available.
Begin by looking for a small or narrow region. If an area has only one square, its cat belongs there. Otherwise, list the positions it could occupy without deciding too early. A region confined to one row reserves that row for its eventual cat, even before you know the exact square. You can therefore exclude positions in that row belonging to other regions. The same idea applies when all candidates share a column.
Once you place a cat, check four things: its row, its column, its color region and the squares touching it. Every other position in those units is unavailable. Diagonal neighbors count as touching just as edge neighbors do. Turn on Mark to record exclusions with crosses, then scan for a row, column or region with a single legal position remaining. Marks are manual notes, so the game does not automatically add or validate them.
A useful rhythm is to make one deduction, update the affected exclusions and scan again. Avoid filling several plausible positions merely because they do not yet turn red. A move can satisfy the current board while still leading to a dead end later. If you cannot justify a choice, leave it as a candidate and examine another part of the grid. Each generated puzzle is checked for exactly one complete solution, but that does not promise every step will be obvious.
The same three placement rules apply to every tier. Start with a grid where you can comfortably distinguish the region outlines and tap each square. The names Easy, Medium, Hard, Expert and Master are convenient size labels; they do not certify that every puzzle in one tier is harder than every puzzle in another. You can switch sizes using the dropdown above the board or open a dedicated size page below.
The five-by-five board has twenty-five squares and needs five cats. It gives you a compact place to learn how rows, columns and irregular regions interact. Try explaining each placement before you tap it. Because fewer squares are visible at once, it is convenient for practising the controls or playing on a smaller screen. A fresh arrangement can still require careful thought; Easy describes its size rather than guaranteeing an effortless solution.
Play easy Cat SudokuThe six-by-six board needs six cats across thirty-six squares. It matches the size used by the daily puzzle, making it a useful practice choice before trying that date’s fixed arrangement. Pay attention to regions spanning several rows and to deductions that reserve a row without fixing the cat’s exact square. Practice boards are generated separately from the daily; solving one does not replace your daily result or increase the daily streak.
Play medium Cat SudokuThe seven-by-seven board contains forty-nine squares and needs seven cats. There is more space to lose track of an exclusion, so a consistent marking routine becomes useful. After each placement, review the affected row, column, color and neighboring squares before moving elsewhere. Choose this size when the compact grids feel familiar and you want a broader board to organize, rather than expecting a particular level of rated solving difficulty.
Play hard Cat SudokuThe eight-by-eight board needs eight cats among sixty-four squares. Instead of scanning randomly, follow a repeatable route through the rows, columns and regions. When a region’s candidates all share one line, record what that reserves elsewhere. Keyboard movement can make a systematic pass easier on a desktop, while a larger screen may help with precise taps. The Expert label indicates the eight-by-eight format, not a guarantee of advanced logical techniques.
Play expert Cat SudokuThe nine-by-nine board has eighty-one squares and needs nine cats. Its dimensions resemble a classic sudoku grid, but it still has one cat per row, column and irregular color region, with no touching cats. It does not use digits or three-by-three boxes. Work in small passes, keep exclusions justified and use Undo when an assumption fails. Master is our largest size category; it does not promise the most difficult possible puzzle.
Play master Cat SudokuTap a square to place a cat, then tap it again to remove it. Mark switches the same action to adding or removing an exclusion cross. Erase clears the selected occupied square, and Undo restores the previous move. Red cells with white cats identify a conflict. The plain text beneath the tools explains whether the cats share a row, column or region, or touch one another. Removing the conflicting cat clears that warning.
Hint is available when you want help continuing, but it reveals an answer rather than explaining a deduction. It removes an incorrectly placed cat or adds a correct cat from the unique solution. If you want to learn from it, pause afterward and examine what that position excludes. On a keyboard, Tab enters the board, arrow keys move between squares without wrapping at an edge, and Enter or Space uses the current cat or Mark mode. Tab also leaves the board.
No. Plainoku is a Queens-style placement puzzle. Each row, column and irregular colored region contains one cat, and cats cannot touch, even diagonally. Classic sudoku instead fills digits into rows, columns and boxes. The Cat Sudoku name describes the cat-themed experience here, not identical rules.
Yes. Plainoku’s puzzles and hints are free, with no advertising, payment flow or subscription. You can start directly in your browser. Other games with similar names may have different prices or monetization; this statement describes Plainoku only, not every cat puzzle on the internet.
Neither is required for Plainoku. Open a size page and use the board. Your current puzzle and statistics are saved locally in this browser. There is no account-based cloud sync, so another device, browser or website origin begins with its own progress.
Color is only one of the constraints. Cats in separate regions can still share a row or column, or occupy touching squares. Check all three units and the eight possible neighbors around a placed cat. The explanation below the tools identifies the rule that a conflicting pair violates.
They correspond to five-by-five through nine-by-nine boards, with one cat needed for each row. These are size categories, not calibrated ratings of deduction complexity. Region shapes vary between puzzles. Pick a size that is comfortable to inspect rather than treating the label as a promised challenge level.
No. Crosses are your manual working notes. Winning depends on correctly placed cats, not on marking every unused square. A mark can be mistaken without causing a red conflict. Review or remove exclusions that relied on a cat you later erase or undo.
Hint reveals a correct answer position or removes an incorrect cat. It does not generate a step-by-step logical explanation. For a learning exercise, examine the row, column, region and neighboring squares affected by the hint, then make your next exclusion or placement yourself.
The daily is a fixed six-by-six arrangement for your local calendar date. Completing it again on the same date does not add another daily solve or extend the streak. The completion button offers a fresh practice puzzle, keeping ordinary practice separate from the daily result.
Yes. On a phone, tap squares and use the tools below the board. On a keyboard, Tab enters or leaves the board, arrows move without edge wrapping, and Enter or Space places a cat or uses Mark mode. Choose a smaller grid if accurate tapping feels uncomfortable.
The current puzzle and statistics stay in this browser when local storage is available. Clearing site data can remove them. Another device or a different origin, including an old Vercel address, does not automatically share this save. There is no sign-in recovery or cross-device transfer feature.
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