Printable evil sudoku sheets with 22 to 25 clues per grid. Each has one solution and needs a forcing chain somewhere, beyond X-wings and swordfish. Print 1 to 12 puzzles with answers at the end. The PDF is made in your browser: no app, no sign-up, no interstitial, works offline and with the keyboard.
Evil grids need every technique up to Expert and then at least one forcing chain: pick a cell with two candidates, assume one, follow the forced singles, and if you reach a contradiction the other candidate is right. A very few need longer trial and error.
Chains are harder on paper than on screen, because you cannot undo. Two habits help. First, write the assumption in a different colour or very lightly, so it can be erased cleanly. Second, test with a photocopy or a second print of the same sheet code, keeping the original clean.
Start chains from two-candidate cells whose digits have few other options. Take the grid as far as possible with pairs and wings first; a chain is much shorter near the end.
Evil sheets suit experienced solvers and puzzle clubs. One grid can fill a long train ride.
If a chain goes wrong and the grid becomes a mess, you can type the givens into the sudoku solver, which shows the next logical step and names the technique, or print a fresh copy from the same sheet code and start again from where the grid was still clean.
Pages are titled "Evil Sudoku" with the sheet code, a rule line, numbered puzzles and page numbers; solutions follow in the same layout. The PDF is built on your device.
Evil sudoku sheets can be made on a phone and printed from any PDF viewer. Tidy Puzzles runs entirely in your browser: there is no app to install, no account to create and no interstitial before you can play. After the first visit the game also works offline, because each puzzle is generated on your device from a seed. Every board can be played with the keyboard alone, on a phone or a desktop, and your stats and unfinished puzzles stay in this browser rather than on a server.
Between 22 and 25.
They need a forcing chain, which is a test followed to a contradiction. A very few need trial and error.
Yes. Every grid is checked for exactly one solution.
Yes, on separate pages at the end.
About 16 cm wide on A4 or Letter.
PDF sheets at any level, with solutions at the end.
22 to 25 clues, needs a forcing chain.
24 to 27 clues, X-wing and swordfish.
26 to 30 clues, pairs and triples.
Solve, check or step through any grid you type in.
Themed word search PDFs with a word bank.
Last updated 2026-09-27. Written and maintained by the Tidy Puzzles team; puzzles are generated on your device. How it works.