What makes Expert Sudoku hard?
An Expert puzzle starts with just 25 givens - two above Evil, and it feels like it. The count is only half the story, though: a board with 25 givens can still fall to plain scanning, so every Expert puzzle here is checked before it is dealt and only ships if finishing it needs at least pointing pairs. That is the line between Expert and Hard on this site, and it is a promise about the solving, not about the number of clues. The beginner tools will place a few numbers and then dry up almost entirely. Where Hard puzzles bend to a naked pair or a pointing pair, Expert grids often need a genuine advanced pattern before anything moves at all.
What separates Expert from Evil is mostly how often you need the hard stuff. On Expert, a well-placed X-Wing usually breaks the grid open and the rest falls into place. On Evil, you might need several of those breakthroughs in a row. Expert is the level where the advanced techniques stop being optional and start being the whole game.
The techniques it demands
You'll lean on the advanced patterns here - the ones that eliminate candidates across the whole board rather than one unit at a time:
- X-Wing Sudoku Technique Explained - One digit confined to the same two columns across two rows (or vice versa) - eliminate it from the rest of those lines.
- Forcing Chains - Follow both values of a bi-value cell; if both branches force the same digit somewhere, that conclusion is certain.
The X-Wing is your bread and butter at this level, and forcing chains are the fallback for the rare grid that resists everything else. If those names are new, the Sudoku School builds up to them one technique at a time.
How to beat Expert Sudoku
Players who move up from Hard usually try to solve Expert the same way they solved Hard - faster scanning, more effort, more staring. That does not work, because the bottleneck is different. Expert grids are not asking you to look harder; they are asking you to look differently.
Three changes make the difference:
- Mark first, solve second. On Hard you can fill candidates in as you go. On Expert, do a full pass of pencil marks before you place anything. The patterns that unlock the grid are properties of the whole candidate layout, so they simply do not exist until the layout is complete.
- Think in units, not cells. Beginners ask "what goes in this cell?" Expert solving asks "where can this digit go in this row?" - the same information, but the second question is the one that exposes X-Wings and pointing pairs.
- Accept slow stretches. A good Expert grid has one or two genuine bottlenecks where nothing is forced for several minutes. That is the puzzle working as designed, not you failing. The breakthrough is usually one eliminated candidate away.
Expect a real sitting rather than a coffee break - and count a finished Expert grid as an achievement, because most players never get past Hard.
To see all three at work on a single grid, we walked one real Expert board through the stall: scanning places three digits, dies with fifty-three cells empty, and one eliminated candidate is worth sixteen more.
How to break a stuck Expert grid
- Full pencil marks, no exceptions. You cannot spot an X-Wing by eye - every candidate has to be on the board first.
- Hunt one digit across the whole grid. The advanced single-digit patterns only appear when you track a number everywhere it could go, not box by box.
- Trust the logic. There is always a deduction. If you're tempted to guess, there's a pattern you haven't found yet.
Think you've got Expert handled? Evil Sudoku is the final step up - 23 givens and no easy moves at all.
Prefer it on paper?
Every level here is also available as a printable sheet. The printable expert Sudoku page builds PDF pages at this exact difficulty - handy for a commute, a classroom, or anywhere a screen is in the way.
All five difficulty levels
Difficulty on SudokuStreak starts with how many digits the puzzle gives you, but the clue count is not the whole answer - and we can show that rather than assert it. On 31 August 2026 we generated 40 boards at every level and had our own solver finish each one, recording the hardest technique it was forced to use. The result was uncomfortable: 28 of the 40 Expert boards needed nothing harder than a hidden single, which is what Medium asks for. A 25-clue grid can still be a scan.
So Expert and Evil are no longer dealt straight from the generator. Boards for those two levels are measured first, away from the site, and only the ones that genuinely need the harder techniques are kept and handed out. That is what the last column below means: always is a floor the puzzle cannot fall below, usually is what the measurement found without one. The counts are for a standard 9×9 board:
| Level | Givens | Hardest technique needed (measured) |
|---|---|---|
| Easy Sudoku | 36 | usually naked single |
| Medium Sudoku | 30 | usually hidden single |
| Hard Sudoku | 26 | usually hidden single |
| Expert - you are here | 25 | always pointing or harder |
| Evil Sudoku | 23 | always box/line or harder |
The names are not standardised, though: "Expert" is the fourth rung of five here and the fourth of six elsewhere, and the hardest tier is called Evil on some sites and Extreme on others. Sudoku difficulty levels explained compares the common ladders and says what each level here actually asks of you.
Frequently asked questions
How many numbers does an Expert Sudoku puzzle start with?
Every SudokuStreak Expert puzzle on a standard 9×9 board is generated with 25 given digits, out of the 81 cells in the grid. Variants built on a different board set their own count for the same level - Samurai, for instance, is five overlapping 9×9 grids and fills each of them separately.
Do the puzzles always have exactly one solution?
Yes. However few givens a puzzle starts with, it has exactly one solution, and that solution is reachable by logic alone.
Do I ever have to guess?
No. Every puzzle can be finished by pure deduction. If you feel you have to guess, there is a technique on the board you have not spotted yet.
Is Expert Sudoku free to play?
Yes - every puzzle on SudokuStreak is free to play in your browser, with no account required. Signing in only adds streaks, scores and the leaderboard.
Is Expert Sudoku harder than Evil?
No - Expert is one step below Evil here: 25 givens against 23. It asks for the same family of advanced patterns, such as the X-Wing and forcing chains, with a little more room to breathe. It is the sensible level to build them up on before dropping to Evil.
Can I print Expert Sudoku puzzles?
Yes. The printable expert Sudoku page generates PDF sheets at this exact difficulty, ready to print. You can start from the printable expert page.