Mini Sudoku Rules, Strategy, and How to Play 6x6 Sudoku Online
Mini Sudoku is Sudoku shrunk down to a coffee break. Instead of the classic 9x9 grid, you get a 6x6 board split into six boxes of two rows and three columns, and the digits 1 to 6. The logic is the same one that made Sudoku a worldwide habit, but a game lasts a few minutes, which makes it a great warm up, a daily ritual, or a gentle first step for anyone who finds the full size puzzle intimidating.
The rules
Fill every empty cell with a digit from 1 to 6 so that:
- each row contains every digit exactly once,
- each column contains every digit exactly once,
- and each 2x3 box, outlined by the thick lines, contains every digit exactly once.
The digits on gray cells are the clues. They are part of the solution and can't be changed. Every puzzle on Lofi and Games is checked by a solver and has exactly one solution, so you can always reach it with logic alone, without guessing.
How to play online
Click or tap a cell to select it, then press a digit on the number bar below the board or on your keyboard. Erase, Backspace or 0 clears the cell. The arrow keys (or W, A, S and D) move the selection. When you select a cell, its row, column and box are shaded, and the other cells with the same digit are outlined, which makes it easy to see where a digit can still go. If a digit repeats in a row, column or box, it turns red. Zoom in, drag the board around or turn on the magnifying glass in the settings if the cells are small on your screen.
Turn on Notes (or press N) to pencil in the digits a cell could still take; you can also hold Shift while typing a digit. Placing a digit removes it from the notes of every cell that shares its row, column or box. Auto Notes keeps every cell's candidates up to date for you, and Auto Check strikes out wrong digits, at a cost to your score. Undo and redo let you go back and forth, and the Help menu gives a hint, reveals a cell or its notes, or reveals the whole board if you'd rather see the answer.
Strategy for 6x6 Sudoku
Look for the last empty cell
The quickest wins are rows, columns or boxes with five digits already in place. The missing digit is the only one that fits. On easy boards you can solve most of the grid this way.
Naked singles
For any cell, rule out every digit already in its row, column and box. When a single digit is left, that is the answer. Easy puzzles can be solved from start to finish with this technique alone.
Hidden singles
Turn the question around: pick a digit and a box (or a row, or a column) and ask where the digit can go. If only one cell can take it, place it there, even if that cell could hold other digits too. Medium puzzles need this technique.
Pairs and pencil marks
Hard puzzles start with fewer clues and need more than singles. Write notes in the empty cells of a unit. When two cells in the same row, column or box can only hold the same two digits, those digits belong to those two cells, so you can erase them from the notes of every other cell in that unit. In a 6x6 grid, each box spans two rows, so a digit confined to one row of a box is also ruled out from the rest of that row.
Tips
- Scan digit by digit: find every 1, then every 2, and so on.
- Boxes are only two rows tall, so cross check rows and boxes often.
- Use notes on hard puzzles instead of keeping candidates in your head.
- Hints add time to your score, so try one more scan before asking for help.
Difficulties, daily puzzle and leaderboard
Easy boards start with 16 clues and fall to naked singles. Medium boards have 12 clues and need hidden singles. Hard boards have about 10 clues and need pairs or other deeper logic. The daily puzzle is the same for every player and changes every day. Your score is your time in seconds plus penalties for hints, revealed cells and notes, and the automatic helpers, divided by 2 on medium and 4 on hard, like Sudoku's. Smaller is better, and the leaderboard ranks the best scores for each difficulty.
A short history
Sudoku grew out of Latin squares, studied by Leonhard Euler in the 18th century. The modern puzzle with boxes appeared in Dell Magazines in 1979 as Number Place, and Nikoli made it famous in Japan in the 1980s under the name Sudoku. Smaller 6x6 versions have long been popular in children's puzzle books and newspapers, and they have found a new audience as quick daily puzzles you can solve on your phone.
The sound effects used on the game come from multiple parties. The credits and respective licenses are listed below:
This game is a property of Lofi and Games. All code and assets are protected and must not be redistributed or used without prior permission.