Expert Printable Sudoku
Expert Sudoku starts with only 20–25 given digits — barely a quarter of the grid. Advanced techniques like X-Wing, Swordfish, and forcing chains are needed. These puzzles can take well over an hour and are genuinely rewarding to complete.
Want to solve instead of print? Jump straight into a puzzle.
▶ Play Expert Sudoku
Generate Expert Puzzles
Given digits:
20–25
20–25
Avg. solve time:
45–90 min
45–90 min
Recommended age:
Any (advanced)
Any (advanced)
Techniques needed:
5 types
5 types
Who This Level Is For
Dedicated enthusiasts, competition preparation, serious challenge.
Expert puzzles are for dedicated Sudoku enthusiasts. Every placement requires careful reasoning. Many cells will not yield until advanced techniques are applied across multiple units simultaneously.
Printing Tips for Expert
- Print 1 per page with wide margins for chain notation.
- A mechanical pencil gives precision for tiny candidate grids.
- Allow uninterrupted time - These puzzles demand full focus.
- Select "Background graphics" in print settings for sharp borders.
- Print at 100% scale - Do not scale to fit.
Expert Sudoku - Complete Guide
All Printable Levels - At a Glance
Techniques Required - Expert
| # | Technique | Frequency |
|---|---|---|
| 1 | X-Wing | Every puzzle |
| 2 | Swordfish | Most puzzles |
| 3 | XY-Wing | Some puzzles |
| 4 | Chains | Occasionally |
| 5 | Forcing Chains | Rarely |
How to Approach Expert Puzzles on Paper
Step 1 - Exhaust all basic techniques first
Before reaching for X-Wing or chains, verify that all singles, pairs, triples, and pointing pairs have been applied. Expert puzzles require advanced logic, but always resolve as much as possible with simpler techniques first - Advanced steps are only needed when the grid is fully stuck.
Step 2 - Apply X-Wing when stuck
An X-Wing exists when a digit appears as a candidate in exactly two cells in each of two rows, and those cells are in the same two columns (or vice versa). The digit must occupy one of two diagonal patterns - Eliminating it from all other candidates in those columns (or rows).
Tip - Chain notation on paper
When using forcing chains, note each hypothesis with a letter (A=true, A'=false) in the margins. Trace both branches: if A leads to a contradiction, A must be false. Paper gives you the luxury of drawing connecting lines between linked cells that digital interfaces can't replicate.
How difficult is Expert? - Relative comparison
Paper vs. Online - Which is better for Expert?
| Scenario | Paper | Online |
|---|---|---|
| Offline access (flights, rural) | ✓ Ideal | - |
| Track personal best times | Manual only | ✓ Automatic |
| Share with friends / classroom | ✓ Print copies | Share link |
| Undo mistakes | Eraser only | ✓ Unlimited undo |
| Hints when stuck | - | ✓ Cell reveal |
| Candidate notation | ✓ Full freedom | Notes mode |
| Leaderboard & scoring | - | ✓ Only online |
Frequently asked questions
Are these puzzles unique? +
Yes. Every puzzle is generated fresh using a randomised backtracking algorithm. Each click of "Generate Puzzles" produces a new set that has never appeared on this site before.
Do expert puzzles always have a unique solution? +
Yes. Our generator verifies that each puzzle has exactly one valid solution before serving it. You will never be forced to guess - Every step can be deduced logically.
Can I get solutions printed too? +
Solutions are not currently included on the printout. For classroom use, you can use our online solver to verify answers - Enter the given digits and hit Solve.
How do I play expert online instead? +
Click below to play in your browser - Includes a timer, unlimited undo, notes mode, hints, and leaderboard scoring.
Play Expert Sudoku Online
Get automatic timing, unlimited undo, mistake tracking, and leaderboard scores.