Medium Mini Sudoku (4×4)

A compact 4×4 grid using digits 1–4. Each row, column, and 2×2 box must contain every digit once. Quick to solve, satisfying to master. Free online.

Easy Medium Hard Expert

Mini Sudoku at medium difficulty. Fewer given digits means you need to cross-reference rows, columns, and 2×2 boxes simultaneously to find each placement.

4
1
2
1
2
3
4
1
3
Mistakes
0/3
Score
-
Time
00:00
Try Hard Mini Sudoku →
Progress0%

What is Mini Sudoku?

Difficulty
★☆☆☆☆
1/5
Constraint Type
Smaller Grid
Typical Givens
4–8
Avg. Solve (Medium)
2 min

Solving Techniques for Medium Level

Technique Description Level
Direct Scanning With only 16 cells and digits 1–4, scan each row, column, and 2×2 box for missing digits. Most easy puzzles resolve in a single pass. Beginner
Single Candidate If only one cell in a row, column, or box can hold a particular digit, place it immediately. Beginner
Box–Row/Column Interaction Each 2×2 box shares all four cells with exactly two rows and two columns. Every box placement simultaneously restricts two full rows and two full columns. Beginner

Master these, then take on Hard Mini Sudoku to learn Advanced techniques.

Techniques to Master at Medium

  • Last Possible Number technique — Cross-reference all three units of a cell and with digits only 1–4, two eliminations already leave a single candidate — medium minis reward exhaustive cell checks.
  • Hidden Singles technique — Even at 4×4, a digit can hide in a multi-candidate cell — when 3 appears in only one cell of a row's candidates, place it regardless of what else the cell lists.

Average Solve Time by Difficulty

Easy
1 min
Medium
2 min
Hard
4 min
Expert
6 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Mini Sudoku →

Related Variants

Alphabet Sudoku

Another gentle twist on the classic — full 9×9 logic with letters A–I standing in for digits.

Consecutive Sudoku

A friendly first marked variant: bars between cells flag consecutive neighbours, and absence of a bar is a clue too.

Kropki Sudoku

When 4×4 grids feel quick, kropki dots add relationship clues that keep beginner-level deduction interesting.

Frequently Asked Questions — Medium Mini Sudoku

What makes medium Mini Sudoku harder than easy?
Medium Mini Sudoku has fewer given digits, so simple row and column scanning is not enough. You need to cross-reference rows, columns, and 2×2 boxes simultaneously to narrow down which digit goes where. Some cells require you to eliminate two or three candidates before the correct digit becomes clear.
Do I need pencil marks for medium Mini Sudoku?
Occasionally. Medium puzzles sometimes leave one or two cells with two equally possible candidates. Jotting down both candidates (just two digits in a tiny space) and then resolving which is correct by checking the intersecting row, column, or box is all you need.
How do I find hidden singles in a 4×4 grid?
For each 2×2 box, check each of the digits 1–4. If only one cell in the box can legally hold a particular digit — because the digit already appears in that cell's row or column — that is a hidden single. In a 4×4 grid, hidden singles appear frequently and are the primary technique at medium difficulty.
How long does a medium Mini Sudoku take?
Medium Mini Sudoku typically takes 2–5 minutes. It is a satisfying quick puzzle that requires genuine logical deduction rather than trivial observation, but still resolves fast. Great for short breaks.
Can a 4×4 grid have a naked pair?
Yes — if two cells in a row, column, or 2×2 box can only hold the same two digits (say, 2 and 3), those two cells form a naked pair. The other cells in the same unit cannot hold 2 or 3. In a 4×4 grid, a naked pair immediately forces the other two cells in that unit to hold the remaining two digits.

More questions? See the full Mini Sudoku guide.