Printable Medium Sudoku: The Step After Easy

A medium sudoku on SudokuIt starts with 21 to 23 givens, seven to nine fewer than an easy one. That gap changes how it feels. Singles are still the main tool, and roughly two medium puzzles in three need nothing else, but with fewer digits on the board they take longer to find. The other third need one move that works on pencil marks.

What you need to know to solve it

• Hidden single. Nearly every medium puzzle leans on it. With 58 or more empty cells, scanning one digit across the boxes is faster than staring at single cells.
• Pointing pair. If a digit's candidates inside a box all sit on one row, that digit can come out of the rest of the row. About one medium puzzle in four (351 of 1,521) finishes once you add this and the next one to singles.
• Claiming group. The same idea turned around: if a row can only put a digit inside one box, it comes out of the rest of that box.
• Naked pair and hidden pair. A few medium puzzles, about one in eight, need one of these to get past a stuck point.

How long it takes

Plan on 20 to 45 minutes. That is a rough guide, not a measurement.

How to print it

Use a pencil. You will not need candidates in every cell, and writing them all out wastes most of the time. Pencil them only where you are stuck, one box at a time. A pointing pair shows up the moment one box's candidates for a digit are on paper.

Each cell is a little under 1 cm, so there is room for three or four small digits. Keep them in the same spot every time, along the top edge, so a placed digit in the middle never gets confused with a note. If you started the puzzle online, tick Progress and Notes to carry on from where you left off.

Who this is for

Solvers who finish easy grids without stopping and want to learn their first pencil-mark technique. It also suits a commute or a lunch break, where an hour-long puzzle would be too much.

See every level on the printable sudoku page, or play medium sudoku online.