How to solve Mini Sudoku

How to solve 6×6 sudoku: techniques that work

The 6×6 grid uses 2×3 boxes, and that box shape is the key difference from classic sudoku. Each box spans two rows and three columns, so a digit placed in a box immediately constrains two full rows. "Box-line" reasoning — if a digit's only spots in a box share a row, erase it from that row elsewhere — fires far more often than in 9×9.

Scan for naked singles first: cells whose row, column and box already contain five of the six digits. On easy boards these chain from start to finish. When they dry up, pick a digit and sweep it: find the boxes where it's missing and intersect rows and columns to see where it can still go.

With only six digits, counting is fast. A row missing 2, 5 and 6 with three empty cells is a small puzzle on its own — check which of the three cells' boxes already contain which digit and the row usually resolves at once.

Common mistakes

Treating the boxes as 3×3 out of habit — in 6×6 they are 2 rows by 3 columns, and half of your eliminations come from that shape. If a deduction feels impossible, re-check which box a cell actually belongs to.

Pencil-marking everything from the start. On a 6×6 it's faster to scan digits systematically; full pencil marks are only worth it on the last few cells of hard boards.

From easy to hard

Easy boards fall to naked singles alone. Hard boards demand box-line eliminations and occasionally a naked pair, but never guessing — like every puzzle on the site, each board is verified to have a single, logically reachable solution.