Merry Christmas! This past year I've added RIPPLE EFFECT, STAR BATTLE, BINOX and INSANE KAKURO puzzles to the site, and I look forward to adding more from my long backlog of new puzzle requests in 2019, during my scant free time. To each of you who has sent an annual donation this month, a HUGE THANK YOU for supporting my work!

Super-Tough Sudoku Puzzles, 4-per-page, Volume 10

Each of my books contains a collection of eight sudoku puzzles, 1-per-page, with a page of hints and a page of answers in the back.

These booklets are in PDF format and need the Adobe Acrobat Reader to view or print.

You can also download all 800 of these puzzles in a 4-per-page format ( with hints and answers, with answers but no hints, or with neither hints nor answers). If you like these puzzles, check out my other puzzles too!

Want to save some trees? Try my Interactive Sudoku, an online version of these puzzles that works on your browser or iPad.

Krazydad Sudokus are also available in a daily puzzle (for print or online).

Problems printing puzzles in Internet Explorer 9? Try these work-arounds.

Here's a blank sudoku grid in case you need to start over.

On the last book? Here's 800 more! (or try my Daily Puzzles)

Click here for the 1-per-page format.