Medium Sudoku – Free Intermediate Online Puzzles

Medium sudoku — also known as moderate — marks the transition from beginner to intermediate play. The number of given clues drops noticeably from easy, and you can no longer rely on scanning alone. These puzzles test your ability to think a step ahead and maintain organised notes. If you've mastered Easy Sudoku, medium is your natural next challenge.

Note: this level is labelled "moderate" in the URL for historical reasons, but the game — and all search engines — know it as medium sudoku.

How to Solve Medium Sudoku

Add these techniques to your toolkit:

• Hidden singles: A digit that can only go in one cell within a row, column, or box — even if that cell has two or three other candidates. These are harder to spot than naked singles but unlock many medium puzzles.
• Cross-hatching (candidate elimination): For a given digit, shade out all rows and columns where it already exists. The intersection reveals where it must go in the remaining boxes.
• Pencil marks: Write small candidate digits in each unsolved cell and eliminate them systematically. At medium level, pencil marks go from optional to strongly recommended.

Tips for Medium Sudoku

• Fill in all pencil marks at the start, then eliminate systematically. Starting with a complete candidate grid makes hidden singles visible immediately.
• When stuck, focus on boxes with 6+ filled cells first. They have the fewest remaining candidates and yield progress fastest.
• Review every pencil-mark update. Eliminating one candidate often reveals a hidden single elsewhere — always re-scan after each step.
• Don't guess. Medium puzzles are fully solvable with pure logic. If you feel forced to guess, revisit your pencil marks for an error.

Why Play Medium Sudoku Daily?

Medium sudoku is the sweet spot for most regular players — challenging enough to feel genuinely rewarding, but achievable within a reasonable time. Once you're completing medium puzzles consistently in under 20 minutes, it's time for Challenging Sudoku.

Frequently Asked Questions

What is medium sudoku?

Medium sudoku introduces hidden singles and cross-hatching techniques. It is the first level where pencil marks become a useful habit for most players.

What is the difference between easy and medium sudoku?

Easy sudoku relies on naked singles and scanning. Medium sudoku adds hidden singles — where a digit can only fit in one cell within a unit even though that cell has multiple candidates.

What techniques do I need for medium sudoku?

Hidden singles and candidate elimination via cross-hatching are the primary techniques. Setting up and maintaining pencil marks in uncertain cells is strongly recommended.

Is medium sudoku good practice for hard puzzles?

Yes. Medium sudoku builds the pencil-mark discipline and hidden-single recognition that are essential prerequisites for tackling Challenging Sudoku successfully.

How long does medium sudoku take to solve on average?

Most regular players finish a medium sudoku in 10 to 20 minutes. Beginners making the jump from easy may need 25 to 35 minutes initially.