Notation

Rows

A row is any 1-by-9 part of the grid. The following grid has the row number in the first position of each row.

 1 . . | . . . | . . .
 2 . . | . . . | . . .
 3 . . | . . . | . . .
-------+-------+-------
 4 . . | . . . | . . .
 5 . . | . . . | . . .
 6 . . | . . . | . . .
-------+-------+-------
 7 . . | . . . | . . .
 8 . . | . . . | . . .
 9 . . | . . . | . . .

We write rN to refer to row N.

Columns

A column is any 9-by-1 part of the grid. The following grid has the column number in the first position of each column.

 1 2 3 | 4 5 6 | 7 8 9
 . . . | . . . | . . .
 . . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . . .
 . . . | . . . | . . .
 . . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . . .
 . . . | . . . | . . .
 . . . | . . . | . . .

We write cN to refer to column N.

Boxes

A box is any of the outlined 3-by-3 regions in the grid. The following grid has the box number in the central position of each box.

 . . . | . . . | . . .
 . 1 . | . 2 . | . 3 .
 . . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . . .
 . 4 . | . 5 . | . 6 .
 . . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . . .
 . 7 . | . 8 . | . 9 .
 . . . | . . . | . . .

We write bN to refer to box N.

Cells

To denote the cell in row M column N, we write rMcN. For example, r3c7 is the cell at the X, and r8c4 is the cell at the Y.

 . . . | . . . | . . .
 . . . | . . . | . . .
 . . . | . . . | X . .
-------+-------+-------
 . . . | . . . | . . .
 . . . | . . . | . . .
 . . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . . .
 . . . | Y . . | . . .
 . . . | . . . | . . .

Snyder Notation

A unit is either a row, column, or box. A candidate is any possible fill for a given cell.

Centre pencil marks denote candidates in a given cell. Corner pencil marks denote (within a box) that the marked number is necessarily in one of the marked cells.

Techniques

I will summarize some techniques below. If you don't like my explanations or want to see someone else's, I think the Learn Sudoku website is pretty clear and concise. In addition, the Sudoku Coach has a lot of high-quality practice puzzles.

Naked Single

If a cell sees all numbers but \( n \), then that cell must be an \( n \) in the finished grid.

 1 . 6 | . . . | . . .
 X . . | 7 8 . | . . .
 . . 5 | . . . | . . .
-------+-------+-------
 2 . . | . . . | . . .
 . . . | . . . | . . .
 3 . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . . .
 4 . . | . . . | . . .
 . . . | . . . | . . .

The X above must be a 9. It sees 1234 in the column, 78 in the row, and 56 in the box.

Hidden Single

If a cell is the only possible position for \( n \) in a given unit, then that cell must be an \( n \) in the finished grid.

 1 . X | . . . | . . .
 3 . . | . . . | . . 2
 . . 5 | . . . | . . .
-------+-------+-------
 . 2 . | . . . | . . .
 . . . | . . . | . . .
 . . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . . .
 2 . . | . . . | . . .
 . . . | . . . | . . .

The X above must be a 2. It is the only position in b1 where 2 is possible.

 . . . | 1 . . | . . .
 . . . | . . . | . . .
 . . . | . . 3 | . . .
-------+-------+-------
 . . . | 2 . . | . . .
 . 3 . | . . . | . . .
 . . . | 4 . . | . . .
-------+-------+-------
 . . 3 | . . . | . . .
 . . . | 6 . . | . . .
 . . . | Y . . | . . .

The Y above must be a 3. It is the only position in c4 where 3 is possible.

Naked Pair/Triple/Quad/…

If a pair of cells in some unit contains exactly a pair of candidates, then those cells must contain that pair of candidates in the final solution.

 . . . | . . . | Y 1 .
 . . . | 4 5 . | . 2 .
 . . . | . . . | X 9 3
-------|-------|-------
 . . . | . . . | . . .
 . . . | . . . | . . .
 . . . | . . . | . . 5
-------|-------|-------
 . . . | . . . | . . .
 . . . | . . . | . . 4
 . . . | . . . | . . .

In the final grid, the cells XY must be 45, but not necessarily in that order. This means that none of the other cells in c7 can be 4 or 5.

The same reasoning applies to any triple/quadruple/etc of candidates in a unit.

X-Wing

 . . . | 9 7 4 | . 6 .
 4 1 6 | 5 3 8 | 9 7 2
 . 7 . | 1 6 2 | 4 3 .
-------+-------+-------
 7 2 4 | 8 1 9 | 3 5 6
 1 5 3 | 2 4 6 | 7 . .
 6 9 8 | 7 5 3 | 2 1 4
-------+-------+-------
 . 4 . | 3 9 1 | 6 2 .
 . . 1 | 6 . 7 | 5 4 .
 . 6 . | 4 . 5 | . . .
Puzz
…974.6.416538972.7.16243.7248193561532467..698753214.4.39162…16.754..6.4.5…
Solution
235974861416538972879162435724819356153246789698753214547391628981627543362485197
Play
https://tinyurl.com/2h6aaeeb

Swordfish

See this forum for a lot of top quality puzzles.

 9 . . | 4 . . | 7 . .
 . 6 . | . 3 . | . 5 .
 . . 1 | . . 8 | . . 4
-------+-------+-------
 2 . . | 8 . . | 1 . .
 . 3 . | . 4 . | . 7 .
 . . 7 | . . 9 | . . 5
-------+-------+-------
 5 . . | 6 . . | 2 . .
 . 2 . | . 8 . | . 9 .
 . . 6 | . . 1 | . . 3
Puzz
9..4..7…6..3..5…1..8..42..8..1…3..4..7…7..9..55..6..2…2..8..9…6..1..3
Solution
952416738468732951371958624245873169639145872817269345583694217124387596796521483
Play
https://tinyurl.com/2dpsluk9

Simple Puzzles

Puzzle 01

 . . . | . . . | . . .
 . 5 . | 7 8 . | 9 . .
 6 . 4 | 1 . . | . . .
-------+-------+-------
 4 . . | . 6 . | . . .
 . . 8 | 5 . 7 | . . 1
 1 . . | 4 . . | . . 3
-------+-------+-------
 . . . | 6 . . | . . .
 5 4 7 | . . . | . . .
 . 1 . | 9 3 . | 4 . 8
Play
https://tinyurl.com/2fklz84c
Puzz
……….5.78.9..6.41…..4…6……85.7..11..4….3…6…..547…….1.93.4.8
Solution
789243165351786924624159837475361289938527641162498753893674512547812396216935478

Puzzle 02

 . . . | 7 . . | 6 . .
 . 7 8 | . 3 . | . . 5
 . 6 4 | . . . | . 1 .
-------+-------+-------
 5 . . | . . . | 2 6 8
 1 4 . | . 6 8 | 7 . .
 . 3 . | . . 2 | . . .
-------+-------+-------
 . . . | . . . | . . 1
 . . . | . . . | 8 7 .
 . . 1 | . 2 . | 5 . 4
Play
https://tinyurl.com/2gwrc7kw
Puzz
…7..6…78.3…5.64….1.5…..26814..687…3…2………..1……87…1.2.5.4
Solution
315794682278136495964285317597413268142968753836572149653847921429351876781629534

Puzzle 03

 . . . | . 7 . | . . .
 7 4 . | . . . | 1 5 .
 2 . 5 | . . . | . 8 .
-------+-------+-------
 . . . | . 9 7 | 8 . .
 . 5 3 | . . . | . 1 9
 1 . . | . 3 . | . . 2
-------+-------+-------
 . 1 . | . . . | . . .
 3 7 2 | . . . | 4 9 .
 9 . 8 | . . . | . . .
Play
https://tinyurl.com/2z7kjw3v
Puzz
….7….74….15.2.5….8…..978…53….191…3…2.1…….372…49.9.8……
Soln
681975324749823156235416987426197835853264719197538642514789263372651498968342571

Puzzle 04

 . 5 . | 8 . 9 | . . .
 8 . . | 1 2 . | 6 7 .
 . . . | . . 4 | . . .
-------+-------+-------
 . . . | . . 7 | . . 1
 . . . | . . . | . . .
 1 9 . | 5 8 . | . . .
-------+-------+-------
 . 1 . | . 9 . | 8 . 2
 . . 7 | . 6 8 | . 9 .
 . 2 . | . 4 . | . . 7
Play
https://tinyurl.com/2nom583d
Puzz
.5.8.9…8..12.67……4……..7..1………19.58…..1..9.8.2..7.68.9..2..4…7
Soln
256879413849123675371654928465937281782416359193582746614795832537268194928341567 https://tinyurl.com/2g9d529c#Replay

Puzzle 05

 . . . | . . . | . 5 .
 . . 7 | 3 . 8 | 6 . .
 8 . . | . 9 2 | . . 3
-------+-------+-------
 . . . | 8 . . | . . .
 . . 6 | . . 9 | 1 3 .
 . 3 . | 2 . . | 7 . .
-------+-------+-------
 . . . | 6 . . | 3 . 9
 . . . | . 2 . | . 8 .
 . . . | 9 . 1 | . 7 .
Play
https://tinyurl.com/2znvbvyf
Puzz
…….5…73.86..8…92..3…8…….6..913..3.2..7…..6..3.9….2..8….9.1.7.
Soln
329146857417358692865792413751863924246579138938214765172685349693427581584931276 https://tinyurl.com/2fdp9t7w#Replay

Easy Puzzles

Puzzle 06

 . 6 . | 5 . . | . . 1
 3 8 . | . . . | 6 . .
 5 . . | . 3 . | . . 8
-------+-------+-------
 . 2 . | 9 8 . | . . .
 . . . | 3 . 4 | . 6 .
 . . . | 2 . . | . . 5
-------+-------+-------
 . . . | . 4 1 | 3 . .
 . 3 . | 8 . . | 9 . 6
 . . . | . . . | . 2 .
Play
https://tinyurl.com/2m2zm6o4
Puzz
.6.5….138….6..5…3…8.2.98…….3.4.6….2….5….413…3.8..9.6…….2.
Soln
967528431381479652542136798426985173875314269193267845259641387734852916618793524 https://tinyurl.com/2z8urd4u#Replay

Puzzle 07

 . . . | . . . | 6 4 1
 . . 2 | . . . | . . .
 5 . . | . 3 . | 2 . .
-------+-------+-------
 . . 7 | . . . | . . .
 . 1 . | . . . | 5 3 4
 6 . . | . . . | 1 . 7
-------+-------+-------
 . 9 . | . 4 . | . . 3
 . . 3 | 5 . 2 | 7 . .
 . 2 . | . . 9 | . 5 .
Play
https://tinyurl.com/2jvd4z2r
Puzz
……641..2……5…3.2….7…….1….5346…..1.7.9..4…3..35.27…2…9.5.
Soln
938257641142896375576134298387415962219768534654923187795641823463582719821379456 https://tinyurl.com/2pvyyqfv#Replay

Puzzle 08

 4 . . | . . . | . 3 6
 . 7 . | 2 9 . | . . .
 . . . | 6 . . | . . .
-------+-------+-------
 6 . . | 9 . . | . . 2
 . 3 9 | . 2 . | . 6 1
 2 . 4 | 8 . 1 | 7 . .
-------+-------+-------
 1 . 3 | . . . | 4 8 .
 7 . . | 4 . . | . . .
 . . . | . . . | . . .
Play
https://tinyurl.com/2e2oejeb
Puzz
4……36.7.29…….6…..6..9….2.39.2..612.48.17..1.3…48.7..4…………..
Soln
482157936376298154591643278617935842839724561254861793123576489768419325945382617 https://tinyurl.com/2oxzfhl3#Replay

Puzzle 09

 8 . . | . . . | 6 9 .
 . . . | . . 4 | . . .
 7 . 2 | . 6 . | 8 . 1
-------+-------+-------
 . . . | . 9 7 | . . 8
 . . . | . . . | . . .
 1 . . | . . . | . . 7
-------+-------+-------
 2 8 . | 3 1 . | . . .
 . . 1 | . 4 2 | . . 9
 4 . 7 | . . 9 | 1 . 3
Play
https://tinyurl.com/2kumbhzc
Puzz
8…..69……4…7.2.6.8.1….97..8………1…….728.31……1.42..94.7..91.3
Soln
835271694916854372742963851524197368673428915198536247289315476361742589457689123 https://tinyurl.com/2zgrrt85#Replay

Puzzle 10

 . . . | . 3 . | . . 1
 5 . . | 1 . . | . 9 .
 . 9 . | 5 . . | . 2 8
-------+-------+-------
 . 5 . | . . 6 | . . .
 . 2 3 | 8 . 7 | . 6 .
 . . . | . 1 3 | . . 7
-------+-------+-------
 . . 7 | . . . | . . .
 . . . | 6 8 . | . . .
 . 6 8 | . 7 . | . . 9
Play
https://tinyurl.com/2fx2njfo
Puzz
….3…15..1…9..9.5…28.5…6….238.7.6…..13..7..7………68…..68.7…9
Soln
682739541574128396391564728759246813123857964846913257417392685935681472268475139 https://tinyurl.com/2f6btd7h#Replay

Intermediate Puzzles

Puzzle 11

 . . . | . 7 . | 2 . .
 1 . . | 3 5 . | 7 . 6
 . . 9 | . 2 1 | 3 5 .
-------+-------+-------
 6 1 . | . . . | . 7 .
 . 3 . | . . . | . 2 .
 . . 4 | . 3 . | 5 . .
-------+-------+-------
 . 2 . | . . . | . . .
 . . 7 | . . 6 | . 9 .
 . 4 . | . . . | . . .
Play
https://tinyurl.com/26o33nda
Puzz
….7.2..1..35.7.6..9.2135.61…..7..3…..2…4.3.5…2………7..6.9..4…….
Soln
563874219182359746479621358615942873738165924294738561926513487357486192841297635 https://tinyurl.com/2dvoecgk#Replay

Puzzle 12

 . 6 7 | . 1 . | . . .
 . . . | . 8 4 | 7 . 2
 . . . | . . 5 | 6 . .
-------+-------+-------
 . 9 . | . . . | 2 . .
 . 1 4 | . . . | . . .
 . 7 5 | . 6 . | 1 8 .
-------+-------+-------
 . . . | . 7 . | . 6 .
 . . 9 | . . . | . 4 .
 . . 8 | . 9 . | . . .
Play
https://tinyurl.com/2pjsa4gs
Puzz
.67.1……..847.2…..56…9….2…14…….75.6.18…..7..6…9….4…8.9….
Soln
567912438931684752482735619896541273314827596275369184143278965629153847758496321 https://tinyurl.com/2pl23537#Replay

Puzzle 13

 5 . . | . 7 9 | 2 4 .
 . . . | . . . | 3 9 .
 . 8 . | . . . | . 5 .
-------+-------+-------
 . . 7 | . . 6 | . . .
 . . . | . . 2 | . . .
 . 3 . | . 4 . | . 7 .
-------+-------+-------
 3 . . | . . . | . 8 6
 . 5 . | . 2 . | . . .
 7 4 . | 8 . . | . 3 .
Play
https://tinyurl.com/2kf2pjvz
Puzz
5…7924…….39..8…..5…7..6……..2….3..4..7.3……86.5..2….74.8…3.
Soln
563179248274568391189234657817356429495782163632941875321497586958623714746815932 https://tinyurl.com/2p5hr969#Replay

Puzzle 14

 . . . | 9 . . | . . 3
 . . 5 | . 8 . | 1 . .
 . . . | . . . | 6 8 5
-------+-------+-------
 9 . 3 | 1 . . | . 6 .
 5 7 . | 4 . 9 | . . .
 . . 4 | . 6 7 | . . .
-------+-------+-------
 . . . | . . 4 | 3 1 .
 . . . | 7 . . | 5 . 8
 . . . | . . . | . 4 .
Play
https://tinyurl.com/2zd6jysd
Puzz
…9….3..5.8.1……..6859.31…6.57.4.9…..4.67……..431….7..5.8…….4.
Soln
618975423245683179397241685923158764576429831184367952752894316461732598839516247 https://tinyurl.com/2nc8fx9v#Replay

Puzzle 15

 . 1 . | . 6 . | . 5 2
 . 8 . | 9 2 . | . 6 .
 . . . | . . 5 | . 1 3
-------+-------+-------
 . . 8 | . . . | . . .
 . . . | . . . | . . .
 4 9 5 | . . . | 6 . .
-------+-------+-------
 . . . | . 9 . | . 3 4
 9 . . | . 8 . | . . .
 . . 4 | 2 5 3 | . . .
Play
https://tinyurl.com/2hdrsjec
Puzz
.1..6..52.8.92..6……5.13..8……………495…6……9..349…8……4253…
Soln
719364852583921467246875913128649375367518249495732681852196734931487526674253198 https://tinyurl.com/2qv4czcr#Replay

Expert Puzzles

Puzzle 16

 . 4 . | 8 . . | . . 5
 . . 5 | . . 6 | . . .
 . . . | . 4 9 | 6 8 .
-------+-------+-------
 5 . . | 3 1 . | . 6 .
 . 6 . | . . 8 | 2 4 .
 . . 2 | . . . | . . 9
-------+-------+-------
 3 . . | . . 1 | . . .
 . 2 . | . . . | . 9 .
 1 . . | . . . | 4 . .
Puzz
.4.8….5..5..6…….4968.5..31..6..6…824…2…..93….1….2…..9.1…..4..
Play
https://tinyurl.com/yoxonk24

Puzzle 17

 4 5 . | . . . | 9 6 7
 . 3 8 | . . 6 | . . .
 1 . . | . . . | 5 . .
-------+-------+-------
 . . . | . . 9 | 7 . 1
 . . . | . 1 . | . . 4
 . 1 . | 7 6 4 | . 5 .
-------+-------+-------
 . . . | 6 . . | . 3 9
 8 . . | . 9 . | . . .
 . . . | 3 . . | 1 . .
Puzz
45….967.38..6…1…..5…….97.1….1…4.1.764.5….6…398…9…….3..1..
Play
https://tinyurl.com/yw2vzbcn

Puzzle 18

 4 . 1 | . . . | . . .
 . 8 . | 7 4 . | . . .
 . 7 . | . . . | 9 6 .
-------+-------+-------
 . 2 . | 4 7 . | . . 6
 8 . . | 9 3 . | . . .
 . . . | . 2 6 | . 1 .
-------+-------+-------
 . . . | 6 . 8 | . . .
 1 . 2 | . 9 . | 4 8 .
 . 9 . | . . . | . . .
Puzz
4.1…….8.74…..7….96..2.47…68..93……..26.1….6.8…1.2.9.48..9…….
Play
https://tinyurl.com/ysug3ldz

Puzzle 19

 . . . | . . . | . 4 8
 . . 5 | 9 . 7 | . . .
 . . . | . 3 8 | . . .
-------+-------+-------
 . 4 . | . 1 . | . . .
 . 3 . | . 4 5 | 7 . .
 . 9 . | 8 . . | . . .
-------+-------+-------
 . 5 . | . . . | . . 1
 . . 6 | . 7 . | 8 . 9
 . . . | . . . | . 7 .
Puzz
…….48..59.7…….38….4..1…..3..457…9.8……5……1..6.7.8.9…….7.
Play
https://tinyurl.com/2x4jw6cn

Puzzle 20

 . . . | . 1 7 | 3 . 9
 . 1 . | 9 . . | . 4 2
 . . . | . 6 . | . 1 .
-------+-------+-------
 2 . . | . . . | . . .
 8 4 . | 3 . 9 | . . 7
 1 . . | 2 . . | 8 6 .
-------+-------+-------
 . 7 9 | . . . | . . .
 . . . | . . . | 2 9 .
 6 . . | . . . | . . .
Puzz
….173.9.1.9…42….6..1.2……..84.3.9..71..2..86..79…………29.6……..
Play
https://tinyurl.com/ytmg7bnl

X-Wing Puzzles

Puzzle X

 . 9 7 | 3 4 5 | . 1 6
 6 5 4 | 2 1 8 | 3 7 9
 . . . | 6 9 7 | 5 4 .
-------+-------+-------
 7 6 9 | 5 3 2 | 4 8 1
 5 2 1 | 9 8 4 | 6 3 7
 . 4 . | 7 6 1 | 9 2 5
-------+-------+-------
 4 7 5 | 8 2 9 | 1 6 3
 9 3 . | 1 7 6 | . 5 4
 . . 6 | 4 5 3 | 7 9 .
Puzz
.97345.16654218379…69754.769532481521984637.4.76192547582916393.176.54..645379.
Play
https://tinyurl.com/yp744j5y

Puzzle XX

 . 7 3 | 9 5 4 | . 2 8
 . 5 4 | . 8 3 | . . 9
 8 9 . | 7 1 . | 4 3 5
-------+-------+-------
 4 6 . | 3 7 5 | 8 9 .
 5 . 7 | . 9 8 | . 4 .
 9 . 8 | 4 2 . | . . .
-------+-------+-------
 7 . . | 8 4 . | 9 . 3
 . 8 9 | 5 3 7 | . 1 4
 3 4 . | . 6 9 | . 8 .
Puzz
.73954.28.54.83..989.71.43546.37589.5.7.98.4.9.842….7..84.9.3.89537.1434..69.8.
Play
https://tinyurl.com/yuc6oaql

Puzzle XXX

 . 6 . | 2 3 . | 1 5 9
 . 3 . | 1 5 . | 8 . .
 1 . 5 | 6 . 8 | 3 2 .
-------+-------+-------
 7 . . | 5 . 6 | 9 3 .
 . 4 . | 3 . 1 | . . .
 6 . 3 | . 8 . | . . 2
-------+-------+-------
 . . . | 8 . 2 | . . 3
 3 2 1 | . . 5 | . . .
 . . 6 | 4 . 3 | 2 . .
Puzz
.6.23.159.3.15.8..1.56.832.7..5.693..4.3.1…6.3.8…2…8.2..3321..5…..64.32..
Play
https://tinyurl.com/yr9p6p7u

Puzzle XXXX

 . . . | . . . | . . .
 5 7 . | 8 9 . | 6 . 1
 1 8 . | . . . | 7 5 .
-------+-------+-------
 3 . . | . . 8 | . . .
 9 5 . | 4 . . | . . .
 . . . | . 2 . | . 7 .
-------+-------+-------
 . . . | 7 . 3 | 8 6 .
 . 6 . | . . . | 1 . 7
 7 . . | . . 9 | . . 2
Puzz
………57.89.6.118….75.3….8…95.4………2..7….7.386..6….1.77….9..2
Play
https://tinyurl.com/yprtjvl9

Swordfish Puzzles

Puzzle 21

 9 . 1 | . . . | 4 . 6
 . . . | 8 . . | . 5 .
 6 . . | . 5 . | . . 3
-------+-------+-------
 . . . | 7 . 4 | . 3 .
 4 . 9 | . . . | . . .
 . 2 . | 6 . . | . . .
-------+-------+-------
 3 . . | . . . | 5 . .
 . 8 . | 5 . 2 | . 6 .
 . . . | . . . | 1 . 4
Puzz
9.1…4.6…8…5.6…5…3…7.4.3.4.9…….2.6…..3…..5…8.5.2.6…….1.4
Play
https://tinyurl.com/26z39329

Puzzle 22

 4 . 7 | . 8 . | 3 . 2
 . 2 . | . . 5 | . . .
 . . . | . 3 . | . . .
-------+-------+-------
 . 7 . | . . 6 | . 9 .
 6 . 1 | . 2 . | 4 . 8
 . . . | 3 . . | . . .
-------+-------+-------
 . . 3 | . . . | 8 . .
 . 4 . | 2 . . | . . .
 9 . 6 | . 1 . | 2 . 4
Puzz
4.7.8.3.2.2…5…….3…..7…6.9.6.1.2.4.8…3…….3…8…4.2…..9.6.1.2.4
Play
https://tinyurl.com/yvftnzrz

Puzzle 23

 6 . 1 | . . . | 2 . .
 . . . | 2 . . | . . .
 7 . . | . . . | . . 9
-------+-------+-------
 . 5 . | 1 . 8 | . . .
 . . . | . 2 . | 1 . .
 . 8 . | . . . | . 7 .
-------+-------+-------
 2 . . | . 7 . | 4 . 3
 . . . | . . 3 | . 8 .
 9 . . | . 6 . | 7 . .
Puzz
6.1…2…..2…..7…….9.5.1.8…….2.1…8…..7.2…7.4.3…..3.8.9…6.7..
Play
https://tinyurl.com/yq3x3vt5

Puzzle 24

 5 . 3 | . . . | . . 9
 . 4 . | . . 5 | . 1 .
 8 . 1 | . 7 . | 3 . 4
-------+-------+-------
 . 3 . | 1 . . | . 2 .
 4 . . | . 3 . | 6 . 7
 . . . | . . . | . 8 .
-------+-------+-------
 7 . 9 | . . . | . . 8
 . . . | 4 . . | . . .
 3 . . | . 5 . | . . .
Puzz
5.3…..9.4…5.1.8.1.7.3.4.3.1…2.4…3.6.7…….8.7.9…..8…4…..3…5….

Puzzle 25

 . . 1 | . 7 . | . . .
 . 6 . | . . 9 | . 2 .
 4 . . | . . . | . . 3
-------+-------+-------
 . 1 . | 8 . 2 | . 9 .
 . . . | . . . | 5 . .
 . 9 . | . . 5 | . 8 .
-------+-------+-------
 . . 2 | . 1 . | 6 . .
 . . . | 2 . 7 | . 5 .
 3 . 8 | . . . | . . .
Puzz
..1.7…..6…9.2.4…….3.1.8.2.9…….5…9…5.8…2.1.6…..2.7.5.3.8……

Puzzle 26

 . . 2 | . 8 . | 9 . .
 . 3 . | . . 6 | . 4 .
 . . . | . . . | . . .
-------+-------+-------
 . 9 . | 4 . 5 | . . .
 6 . 8 | . . . | . . .
 . 2 . | 7 . . | . 9 .
-------+-------+-------
 1 . 5 | . . . | 6 . .
 . 4 . | . . 7 | . . .
 . . 9 | . . . | 1 . .
Puzz
..2.8.9…3…6.4………..9.4.5…6.8…….2.7…9.1.5…6…4…7…..9…1..

Puzzle 27

 . . 9 | . . . | 4 . 3
 . . . | . . 6 | . . .
 . . 3 | . . . | 2 . 7
-------+-------+-------
 . . . | . . 1 | . . .
 . . 8 | . 4 . | 6 . 2
 . . . | 7 . 8 | . 3 .
-------+-------+-------
 5 . 4 | . 2 . | 8 . 9
 . 8 . | . . 5 | . . .
 1 . . | . . . | . . .
Puzz
..9…4.3…..6…..3…2.7…..1…..8.4.6.2…7.8.3.5.4.2.8.9.8…5…1……..

Puzzle 28

 . . 9 | . 5 . | 6 . 1
 . 7 . | . . 9 | . 5 .
 1 . . | . . . | 2 . .
-------+-------+-------
 . 8 . | 5 . 3 | . . .
 . . 1 | . . . | . . 8
 . 5 . | . . 4 | . 2 .
-------+-------+-------
 3 . 8 | . 7 . | . . .
 . 6 . | 4 . . | . . .
 . . 7 | . . . | 1 . 2
Puzz
..9.5.6.1.7…9.5.1…..2…8.5.3…..1…..8.5…4.2.3.8.7…..6.4…….7…1.2

Puzzle 29

 9 . . | . 2 . | 1 . .
 . 3 . | . . . | . . .
 4 . 2 | . 5 . | 9 . 6
-------+-------+-------
 . 5 . | 7 . . | . . .
 8 . 4 | . . . | . . 2
 . 6 . | . . 5 | . 4 .
-------+-------+-------
 5 . . | . . . | 2 . 8
 . . . | . . 8 | . 3 .
 6 . . | . 1 . | . . 4
Puzz
9…2.1…3…….4.2.5.9.6.5.7…..8.4…..2.6…5.4.5…..2.8…..8.3.6…1…4

Puzzle 30

 . . . | . . . | 6 . .
 . . . | 1 . 5 | . 7 .
 . . . | . 3 . | 4 . 9
-------+-------+-------
 . 2 . | 7 . . | . . .
 8 . 9 | . . . | . . 4
 . 1 . | . . . | . . .
-------+-------+-------
 3 . . | . 4 . | . . 5
 . 6 . | . . 1 | . 2 .
 . . 8 | . 6 . | 3 . 1
Puzz
……6…..1.5.7…..3.4.9.2.7…..8.9…..4.1…….3…4…5.6…1.2…8.6.3.1

Jellyfish Puzzles

Puzzle 31

 . . 9 | . 6 . | 7 . .
 . 4 . | 2 . . | . . .
 6 . 7 | . 3 . | 2 . 4
-------+-------+-------
 . . . | . . . | . . .
 2 . 8 | . 7 . | . . 3
 . . . | 8 . 1 | . 2 .
-------+-------+-------
 3 . 6 | . . . | . . 5
 . . . | . . 3 | . 8 .
 8 . . | . 9 . | . . 7
Puzz
..9.6.7…4.2…..6.7.3.2.4………2.8.7…3…8.1.2.3.6…..5…..3.8.8…9…7
Play
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Puzzle 32

 . 2 . | 4 6 . | . . .
 8 . . | . 1 . | . . .
 3 . . | . . . | 7 2 .
-------+-------+-------
 . . . | . . 1 | 6 . 4
 6 . 2 | . 5 . | . 8 .
 . . . | . . . | . . .
-------+-------+-------
 . . . | . . . | . 5 8
 4 8 . | . . 6 | . 3 2
 . 1 5 | . . . | . . .
Puzz
.2.46….8…1….3…..72……16.46.2.5..8……………..5848…6.32.15……

Puzzle 33

 . . 1 | . . . | . . .
 9 4 . | . . . | . 7 2
 . . 2 | . . . | 6 . .
-------+-------+-------
 . . . | . 6 . | . . 4
 1 5 8 | . 3 . | . . 9
 7 . . | . . . | . . .
-------+-------+-------
 5 . . | 7 . 4 | . . .
 . . . | 6 9 . | . . 3
 . . . | . . . | 2 1 .
Puzz
..1……94…..72..2…6……6…4158.3…97……..5..7.4……69…3……21.

Puzzle 34

 . . . | . 9 . | . 7 .
 8 . . | . . 4 | . . .
 . 5 . | 1 . . | 2 . .
-------+-------+-------
 . . . | . . 7 | . 1 .
 4 . 8 | . . 5 | . . .
 . . 2 | . . . | 8 . 9
-------+-------+-------
 . . 6 | . . . | . . 7
 . . 5 | 4 . . | . . 6
 7 . . | 3 . . | . 4 5
Puzz
….9..7.8….4….5.1..2…….7.1.4.8..5…..2…8.9..6…..7..54….67..3…45

Puzzle 35

 . . 2 | 6 . 1 | . . .
 . 5 . | . . . | . 4 .
 . . . | . 8 . | . . .
-------+-------+-------
 8 3 . | 5 . . | . 1 .
 . . . | 7 . . | . . .
 . . . | . 6 . | . . .
-------+-------+-------
 . . 9 | . . 2 | . 7 8
 . . 4 | . . . | 1 . .
 . . 6 | 3 . . | . . 5
Puzz
..26.1….5…..4…..8….83.5…1….7………6……9..2.78..4…1….63….5

Puzzle 36

 . . 7 | . . . | 2 . .
 . . 9 | 1 6 . | . . 3
 2 . . | . . . | . . .
-------+-------+-------
 . . . | . 2 . | 5 . 9
 . . . | . . 7 | . 8 .
 . . . | 3 . 6 | . . .
-------+-------+-------
 7 . . | . . 3 | 6 . .
 9 . . | . . . | 8 3 .
 6 2 . | . 5 . | 7 . .
Puzz
..7…2….916…32…………2.5.9…..7.8….3.6…7….36..9…..83.62..5.7..

Puzzle 37

 . . 2 | 9 . . | 1 . .
 . 4 8 | . . . | . . .
 . . . | . . . | 2 . .
-------+-------+-------
 . 2 9 | . . 5 | 7 . .
 . . . | . . 3 | 6 . 8
 . 3 . | . . 2 | . . 9
-------+-------+-------
 . . . | 2 . . | 9 . 6
 4 7 . | 6 . . | . . .
 . . . | 5 . 4 | . . .
Puzz
..29..1…48…………2…29..57…….36.8.3…2..9…2..9.647.6……..5.4…

Puzzle 38

 1 . 2 | . . 3 | 7 . .
 . . . | 5 . . | . 4 .
 . 6 . | . . . | . . .
-------+-------+-------
 . . . | . . 4 | 6 5 .
 5 9 . | . . . | . . 8
 . . 8 | . . . | 2 . .
-------+-------+-------
 . . . | . 8 5 | . 6 .
 . 8 . | 7 . 1 | 3 . 4
 7 . . | 6 . . | . . .
Puzz
1.2..37…..5…4..6…………465.59……8..8…2……85.6..8.7.13.47..6…..

Puzzle 39

 . 4 . | . . . | . . .
 . . . | . 7 9 | . . 3
 . 8 6 | 1 . . | 9 . .
-------+-------+-------
 1 . . | . . . | 5 . .
 . . . | 6 . . | . 8 .
 9 . 5 | . . . | 6 . 7
-------+-------+-------
 . . . | 8 1 . | 4 . .
 . . . | . . 7 | . 9 .
 . 5 . | . 6 . | . . .
Puzz
.4………..79..3.861..9..1…..5…..6…8.9.5…6.7…81.4…….7.9..5..6….

Puzzle 40

 . 8 . | . . . | . 5 .
 . . 3 | . . . | . 9 6
 . . . | 4 6 3 | . . 1
-------+-------+-------
 . 9 . | . . . | . 1 8
 . . . | . 2 7 | 3 6 5
 . . . | . . . | . . .
-------+-------+-------
 6 . . | . 5 . | . . 4
 1 . . | . 3 . | . . .
 . 5 . | 7 . 4 | . . .
Puzz
.8…..5…3….96…463..1.9…..18….27365………6…5…41…3…..5.7.4…

Cool Puzzles

Cool 1

 4 . . | . . . | . . 2
 . . 3 | . 7 . | 4 . .
 . 5 . | 9 . 2 | . 3 .
-------+-------+-------
 9 . . | . . . | . . 7
 . 1 . | . 2 . | . 9 .
 6 . . | . . . | . . 3
-------+-------+-------
 . 7 . | 5 . 9 | . 1 .
 . . 1 | . 6 . | 7 . .
 8 . . | . . . | . . 6
Puzz
4…….2..3.7.4…5.9.2.3.9…….7.1..2..9.6…….3.7.5.9.1…1.6.7..8…….6
Play
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