6x6 Sudoku Online Free
The perfect bridge between mini and classic: six digits, 2×3 boxes, games that take five to ten minutes. Free, no sign-up.
Rules of 6x6 Sudoku
- Each row and each column contains the digits 1–6 exactly once.
- Each of the six 2×3 boxes (two rows tall, three columns wide) contains the digits 1–6 exactly once.
The rectangular boxes are the one new idea compared to 4x4 — and the one that trips up newcomers, because a 2×3 box spans more of the grid than a square one looks like it should.
Techniques for 6x6
- Cross-hatching still rules: with only six digits, scanning each digit across rows and columns resolves most cells.
- Watch the box shape: a 2×3 box covers two rows and three columns — mentally highlight it before eliminating.
- Nearly-finished units first: a row with five digits placed forces the sixth.
- Light pencil marks: on medium and hard 6x6 grids, short candidate notes pay off.
From 6x6 to the Full Grid
Once 6x6 feels comfortable, the step to easy 9x9 sudoku is smaller than it looks — the logic is identical, just more cells. Need paper versions? Print free sets from the printable sudoku library, or review the rules and strategies to sharpen up.