Challenge Puzzles

Here are some challenging puzzles with various miscellaneous properties. Many of these may be the most challenging Sudoku puzzles you'll find.

The puzzles are available in printable form as PDF files. Each file contains 100 puzzles, with 2 puzzles per page.

If you really enjoy these puzzles, consider making a contribution to support the continued existence of this web site. Click on the "Contribute to boldts.net" icon at the left to make a $10 payment via PayPal. Think of how much you have to pay for Sudoku books in the store. And think about how many puzzles you can download from this site.

Index

The first batch of miscellaneous puzzles all have 20 seed values, and 2-fold rotational symmetry. These puzzles take a long time to create, roughly 100 puzzles per day. I got impatient after 4000 puzzles.

#1 #2 #3 #4 #5 #6 #7 #8 #9 #10
#11 #12 #13 #14 #15 #16 #17 #18 #19 #20
#21 #22 #23 #24 #25 #26 #27 #28 #29 #30
#31 #32 #33 #34 #35 #36 #37 #38 #39 #40

If you like nonomino puzzles, here are some more, and these are tougher than the others. These have 21 or fewer seed values, and many of them require all of the advanced solving techniques.

#41 #42 #43 #44 #45 #46 #47 #48 #49 #50
#51 #52 #53 #54 #55 #56 #57 #58 #59 #60
#61 #62 #63 #64 #65 #66 #67 #68 #69 #70
#71 #72 #73 #74 #75 #76 #77 #78 #79 #80
#81 #82 #83 #84 #85 #86 #87 #88 #89 #90
#91 #92 #93 #94 #95 #96 #97 #98 #99 #100
#101 #102 #103

And finally, a group of regular puzzles of varying difficulty, each with 19 seed values. These take a long time to produce, so I won't be posting very many of these.

#104

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Answers

#1 #2 #3 #4 #5 #6 #7 #8 #9 #10
#11 #12 #13 #14 #15 #16 #17 #18 #19 #20
#21 #22 #23 #24 #25 #26 #27 #28 #29 #30
#31 #32 #33 #34 #35 #36 #37 #38 #39 #40
#41 #42 #43 #44 #45 #46 #47 #48 #49 #50
#51 #52 #53 #54 #55 #56 #57 #58 #59 #60
#61 #62 #63 #64 #65 #66 #67 #68 #69 #70
#71 #72 #73 #74 #75 #76 #77 #78 #79 #80
#81 #82 #83 #84 #85 #86 #87 #88 #89 #90
#91 #92 #93 #94 #95 #96 #97 #98 #99 #100

#101 #102 #103 #104

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