Hard Sudoku Printable (Free PDF + Generator)
Hard sudoku that is honestly hard: every puzzle requires an X-Wing, XY-Wing or Swordfish to finish, and none can be solved by scanning alone. Download the 24-puzzle pack with answers, or open the generator preset to Hard.
Hard sudoku PDF pack, answers included
A ready-to-print pack from this site's generator, every puzzle single-solution verified and graded Hard by the pattern it needs.
Hard sudoku generator: two per page for pencil room
Preset to Hard at two per page, which leaves the cell size most solvers want for candidates. Every grid is checked for a single solution; the preview is puzzle #1.
Every puzzle is checked for a single unique solution before it prints. Difficulty is graded by the hardest human technique the puzzle actually requires — not by clue count. No signup, no email, no watermark.
What a hard sudoku from this generator looks like
Page one of the pack and the two-per-page generator layout. Hard puzzles show 24 to 30 givens and always contain an X-Wing-class step.
Hard pack, six per page
Hard, two per page
The three patterns every hard sudoku on this page needs
The grader promotes a puzzle to Hard when singles, locked candidates and naked pairs run dry and one of three patterns is required: an X-Wing (a digit confined to the same two columns in two rows, which clears it from those columns elsewhere), an XY-Wing (three two-candidate cells forming a pivot and two wings), or a Swordfish (the X-Wing idea across three lines). Nothing beyond those three appears; a puzzle that needs chains is re-rated Expert.
That makes Hard a learnable tier rather than a wall. Once you can spot an X-Wing in a candidate grid, a hard sheet from this site stops being mysterious and becomes a search for one pattern. Full pencil marks are expected here; the pencil-mark grid with nine candidate squares per cell was drawn for exactly this.
How to solve a hard sudoku when scanning stalls
Fill every candidate first; on a hard puzzle the shortcuts of the medium tier do not pay. Then hunt one digit at a time across the whole grid: a digit that appears as a candidate in exactly two cells of a row, twice, in the same two columns, is an X-Wing, and it removes that digit from the rest of those columns. If no X-Wing shows, look for a cell with two candidates whose two neighbours each share one of them, the XY-Wing pivot.
Expect one such moment per puzzle, sometimes two, and singles the rest of the way. If you want the technique library with worked animations, our sister site PuzzleFuel runs the same daily puzzle with hints; this page is the print side. When Hard feels routine, expert and evil sudoku is next.
Every printable sudoku on this site
Every sudoku template on this site prints the same technique-graded 9×9 puzzle — only the frame around it changes. Pick the one that matches the occasion, or start from a blank sudoku template and write your own.