Online Sudoku

Medium Diagonal Sudoku – Play Free Online

Balance logic across five dimensions with free medium Diagonal Sudoku puzzles online. X Sudoku for solvers who can juggle rows, columns, boxes, and both diagonals. Play instantly on any device.
No download · No signup · Solvable deals · Play in your browser
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What is Medium Diagonal Sudoku?

Medium Diagonal Sudoku (Medium X Sudoku / Medium Sudoku X) makes the diagonal constraint an active part of your solving, not just a bonus.

Along with classic rules, both main diagonal lines must also contain digits 1–9 without repetition, adding two more units to manage.

With 30-35 given numbers, progress often depends on diagonal-based eliminations. It typically feels harder than medium Classic Sudoku.

Why Play Medium Diagonal Sudoku Online?

Our web-based Sudoku platform is built for speed and focus:

  • •⚡ Instant play — no download or signup required
  • •📱 Fully responsive — works on mobile, tablet, and desktop
  • •🧩 Unlimited medium Diagonal Sudoku puzzles
  • •🧠 Designed for brain training and logic improvement

Whether you're looking for a fresh Sudoku twist or want to master diagonal constraints, this is the perfect place to play medium Diagonal Sudoku online for free.

How to Play Medium Diagonal Sudoku

Basic Rules

  • •Fill the 9×9 grid with numbers 1–9
  • •Each row must contain all digits without repetition
  • •Each column must contain all digits without repetition
  • •Each 3×3 box must contain all digits without repetition
  • •❌ Diagonal Rule: Both main diagonals must contain digits 1–9 without repetition

Controls (Web Sudoku)

  • •Click a cell to select it
  • •Use keyboard (1–9) to enter numbers
  • •Press D to toggle notes (draft mode)
  • •Use Delete/Backspace to clear cells
  • •Use hints when needed (limited per puzzle)

🧩 Medium Diagonal Sudoku Solving Techniques

Medium X Sudoku rewards using diagonals to create intermediate eliminations.

Look for diagonal pairs and triples, then combine them with classic techniques.

Key Techniques:

  • ✓Diagonal Pairs — Two diagonal cells share two candidates
  • ✓Diagonal Triples — Three candidates locked on diagonal
  • ✓Diagonal Locked Candidates — Confined within a box
  • ✓Diagonal Intersections — Use overlaps between diagonals and rows/columns/boxes to eliminate candidates.
  • ✓X-Wing on Diagonals — When a candidate appears exactly twice on each diagonal and aligns in the same rows or columns, eliminate that candidate from the rest of those rows/columns.
  • ✓Hidden Pairs on Diagonal — Two digits locked on diagonal
  • ✓Diagonal Candidate Reduction — Use all five constraints

🟡 Medium Diagonal Sudoku FAQ

How difficult is Medium Diagonal Sudoku compared to Easy?

Medium puzzles have 30-35 given numbers (compared to 36-45 in Easy). Progress requires spotting Diagonal Pairs and using Diagonal Candidate Reduction across all five constraint types—rows, columns, boxes, and both diagonals.

What strategies are useful in Medium Diagonal Sudoku?

Use Diagonal Pairs—when two diagonal cells share the same two candidates, eliminate those digits from the rest of that diagonal. Look for Diagonal Triples to lock three candidates. Apply X-Wing on Diagonals when a candidate appears twice on each diagonal.

How do diagonals affect solving strategies in Sudoku X?

Diagonals act as two extra rows/columns. They enable Diagonal Locked Candidates—if a digit on a diagonal is confined to one 3×3 box, you can eliminate it from the rest of that box. They also create unique X-Wing patterns not found in Classic Sudoku.

Why do Medium Diagonal Sudoku puzzles take longer to solve?

Because fewer cells can be solved directly, requiring multi-step reasoning and careful candidate tracking.

Should I use pencil marks for Medium Diagonal Sudoku?

Yes, tracking possible values is important when multiple constraints overlap, especially near diagonal intersections.

🎯 Play Medium Diagonal Sudoku Online Now

Start solving instantly with our free medium Diagonal Sudoku puzzles. No signup, no distractions—just pure logic gameplay with a diagonal twist.

👉 Play now and master the X Sudoku challenge today.

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