24 clues is the most populous bucket in our extreme collection. It marks the threshold where puzzles consistently require wing patterns or short chains - intersection logic alone will not finish the grid.
57 empty cells, dense candidate lists, and at least one chain step on every puzzle. 24-clue puzzles are the workhorse of competitive Sudoku - hard enough to require real technique but common enough that you can build a daily practice rhythm at this count.
24-clue puzzles are the Goldilocks zone of difficult Sudoku - generators produce them in volume, they reliably require advanced techniques, and they almost always have a clean solving path that does not need brute-force chain searches.
Mark all candidates first. Sweep for naked pairs and pointing pairs to compress the candidate space, then scan each digit's positional grid for X-Wings. If a digit appears in exactly two cells of two different rows and those cells share columns, you have an X-Wing eliminator. When that fails, hunt XY-Wing pivots: any cell with exactly two candidates is a pivot candidate. Many 24-clue puzzles unlock with a single XY-Wing.
For deeper coverage of the techniques you will need, see our guides on X-Wing, XY-Wing, Swordfish, and the full Sudoku strategies hub.
This page is part of our Sudoku by clue count cluster. The fewer clues a puzzle has, the more advanced the techniques required. The proven minimum is 17 clues - see 17-clue Sudoku for the famous case. For the matching difficulty band see Extreme Sudoku.
Almost always. The vast majority of 24-clue puzzles require X-Wings, XY-Wings, or short chains. A small fraction can be solved with subset logic alone and would be classified as expert, but in our collection the entire 24-clue set is rated expert or extreme.
Experienced solvers finish 24-clue puzzles in 20 to 35 minutes. If you are spending more than 45 minutes, you are likely missing an X-Wing or XY-Wing - take a screenshot of your candidates and look at each digit's positional pattern across the grid.
A 24-clue Sudoku puzzle starts with 24 digits already placed in the grid out of 81 cells, leaving 57 cells for you to fill. Lower clue counts generally mean harder puzzles because you have less starting information.
Most experienced solvers complete a 24-clue puzzle in 20-35 minutes. Beginners may take significantly longer at this clue count, especially if pencil marks are required.
In our classification, 24-clue puzzles are rated extreme. The exact difficulty also depends on which solving techniques are required - clue position matters as much as clue count.
Yes. Open any puzzle from this page and use the print function in your browser, or visit our printable collection at /printable-sudoku for printer-optimized layouts of extreme puzzles.
Ready to put your skills to the test?
Try Final Sudoku - an ad-free Sudoku experience with smart tools