Sudoku Medium - Play Free Online Puzzles

Play medium Sudoku on LiveSudoku when easy puzzles start to feel routine. Medium boards are still solved by logic, but they ask you to look a little deeper: singles are not always obvious, pencil marks become more useful, and one careful scan can open the whole puzzle. When you get stuck, the smart Hint system acts like a one-of-a-kind Sudoku guide, showing the next step on the board with a full explanation. Choose a board above or start a new game whenever you want a fresh challenge. Prefer paper? Browse our printable medium sudoku puzzles.

Start with the basic sudoku rules

Every row, column, and 3x3 box must contain the digits 1 to 9, each exactly once. Medium puzzles use the same rules as easy puzzles, but they give you fewer immediate openings.

Start with Full House and Naked Singles

Begin with Full House cells and Naked Singles. These are the techniques carried over from easy, and they still solve most of the early board.

Add Hidden Singles and pencil marks

Medium Sudoku introduces Hidden Singles. A Hidden Single is a digit that can only legally go in one cell within a row, column, or box - even when that cell still appears to have several candidates. Use pencil marks to keep track as you eliminate possibilities.

Medium Sudoku is the step between basic scanning and deeper candidate logic. Easy boards are usually solved with Full House cells and Naked Singles - looking at a cell and finding the only digit that fits. Medium boards add Hidden Singles, where you pick a digit and find the only legal spot it can still go inside a row, column or box. Most players can finish a medium puzzle in about 10 to 20 minutes once they are comfortable with the tools.

If medium starts to feel too quick, try Hard Sudoku. If you want a lighter warm-up first, return to Easy Sudoku.

Scan one number at a time

Pick a digit, then scan every row, column, and box for places where that digit can still fit. This keeps your search focused and makes Hidden Singles easier to see.

Use pencil marks only where they help

You do not need to mark every empty cell on every medium board. Add pencil marks when a section feels stuck, then remove candidates as new numbers appear.

Move up when medium becomes routine

When medium puzzles stop slowing you down, the next step is Hard Sudoku, where locked candidates and pairs become more important.

LiveSudoku was created in 2006 by Mr. Izenberg and has offered free online Sudoku puzzles for nearly two decades. The goal is simple: clean Sudoku boards, helpful tools, no downloads, and puzzles for every level from beginner to expert.