6x6 Sudoku
Fill every row, column and 2x3 box with 1 to 6
Sudoku Six is a compact six-by-six sudoku built for people who like the logic of sudoku but rarely have an afternoon to spare. The grid is divided into six boxes of two rows by three columns, and the rule is the classic one: every row, every column and every box must end up holding the numbers one through six exactly once.
What matters here is how the puzzles are made. A complete solution is generated first, then cells are removed one at a time, and each removal is only kept if the remaining grid still has exactly one solution. Nothing is hand-authored and no puzzle is reused, so every board you open is fresh, always solvable by logic alone, and never ambiguous.
Two levels are available. Easy leaves twenty given numbers and is a gentle warm-up, while Tricky leaves fourteen and expects you to hold several candidates in your head at once. Whichever you pick, the game stays out of your way: wrong entries can be flagged in red the moment you place them, or you can switch that off and solve without feedback. There is also a hint button that fills a single cell when a grid genuinely stalls.
The game runs as one self-contained HTML file with no external libraries, no network requests and no tracking. It plays with a mouse, a finger or a keyboard, and it reflows to fit a phone screen in portrait. No account, no download, and a finished grid usually takes under five minutes.
How to play
- Pick Easy (20 given numbers) or Tricky (14 given numbers) to start.
- Select any empty cell, then place a number from 1 to 6.
- Every row, every column and every 2x3 box must contain 1 to 6 exactly once.
- Wrong entries turn red immediately while Check is on; switch it off to solve without hints.
- Fill all thirty-six cells correctly to finish and see your time, mistakes and hints used.
Controls
- Mouse or touch: tap a cell to select, then tap a number on the pad below the grid
- Keyboard: press 1-6 to place a number, arrow keys to move, Backspace or Delete to clear
- Buttons: Hint fills one cell, Erase clears the selection, Menu returns to difficulty select
Tips
- Start with the row, column or box that already has the most given numbers, since it has the fewest candidates left.
- Watch the number pad: a number shown dimmed already appears six times on the board, so it is finished.
- Turn Check off if you want to solve purely by logic without being told a placement is wrong.
Frequently asked questions
Is every 6x6 puzzle guaranteed to have one solution?
Yes. Each puzzle is generated by removing cells one at a time and keeping a removal only when the grid still resolves to exactly one solution.
Can I play without the game telling me when I am wrong?
Yes. Tap the Check button to turn mistake highlighting off. Wrong numbers will no longer turn red and will not be counted.
Does 6x6 Sudoku work on a phone?
Yes. The grid and number pad reflow to fit a portrait phone screen, and you can place numbers by tapping instead of typing.
