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Information -+

Announcement of the maintenance work Dec 11, 2017

from Fri. Dec 15, 2017 05:00(UTC), about 2 hours

You will not able to get access to the nikoli.com during this time. Sorry for the inconvenience.

Result of the 281st nikoli.com Puzzle ChampionshipDec 8, 2017

Congratulations! Hazakura-Hazuki won the 281st Puzzle Championship! The winner's name is now displayed and will remain on the Champion page of nikoli.com Hall of Fame.

The next puzzle championship will be held from Fri. Dec 22, 2017 13:00 (UTC). We will set 2 kinds of problems at the same time. aiko's Ripple Effect and Guten's Hitori are waiting for your challenge.

Added Shikaku, Sudoku and Shakashaka to The pick of the puzzles pageDec 1, 2017

Added Shikaku, Sudoku and Shakashaka to The pick of the puzzles page in the members only corner.

Added Botsu Bako problem Oct 20, 2017

SAKAMOTO, Nobuyuki's Satogaeri problem is open to members. Try it out on the Botsu Bako (Extra Special Problems) page in the members only corner.

Results of the 24 hour janken GameSep 12, 2016

24 hour janken is a simple and easy game. It is a championship with janken (the well known rock-paper-scissors game), which is a popular game among Japanese.

Look here for the results of the 24 hour janken.

Recent puzzles

The problems in the table have been published within the last 1 week (168 hours). You can find older problems in the "Collection of problems".

You can enjoy     cells problems, if you are a member.

TypeSizeLevelAuthorPublished
Masyu18x10

18x10

Medium

T.KarinoDec 12, 2017 03:00(UTC)
Yajilin10x10

10x10

Medium

Subaru_SaitoDec 12, 2017 03:00(UTC)
Solve problemHashiwokakero9x9

9x9

Easy

aquablueDec 11, 2017 15:00(UTC)
Shakashaka36x20

36x20

Hard

cubic functionDec 11, 2017 15:00(UTC)
Heyawake 10x10

10x10

Easy

bay wolf JrDec 11, 2017 03:00(UTC)
Hitori17x17

17x17

Medium

aikoDec 11, 2017 03:00(UTC)
Solve problemNumberlink10x10

10x10

Easy

GutenDec 10, 2017 21:00(UTC)
Satogaeri24x14

24x14

Medium

OglandDec 10, 2017 15:00(UTC)
Ripple Effect18x10

18x10

Hard

CastyDec 10, 2017 15:00(UTC)
Shikaku24x14

24x14

Hard

nyoroppyiDec 10, 2017 03:00(UTC)
Kakuro11x9

11x9

Easy

-4Dec 10, 2017 03:00(UTC)
Solve problemShakashaka10x10

10x10

Easy

aikoDec 9, 2017 21:00(UTC)
Slitherlink36x20

36x20

Hard

alkalineDec 9, 2017 15:00(UTC)
Nurikabe 36x20

36x20

Hard

bay wolf JrDec 9, 2017 15:00(UTC)
Hitori8x8

8x8

Medium

45Dec 9, 2017 03:00(UTC)
Hashiwokakero32x18

32x18

Hard

T.KarinoDec 9, 2017 03:00(UTC)
Heyawake 18x10

18x10

Easy

SAKAMOTO, NobuyukiDec 8, 2017 21:00(UTC)
Akari24x14

24x14

Hard

-4Dec 8, 2017 15:00(UTC)
Masyu24x14

24x14

Medium

bay wolf JrDec 8, 2017 15:00(UTC)
Yajilin

Time trial problem

45x31

45x31

Extra

CastyDec 8, 2017 13:00(UTC)
Shakashaka18x10

18x10

Medium

OglandDec 8, 2017 03:00(UTC)
Satogaeri10x10

10x10

Easy

aikoDec 8, 2017 03:00(UTC)
Norinori24x14

24x14

Medium

Ogawa MinoriDec 7, 2017 15:00(UTC)
Sudoku9x9

9x9

Hard

cubic functionDec 7, 2017 15:00(UTC)
Numberlink18x10

18x10

Medium

GutenDec 7, 2017 03:00(UTC)
Solve problemRipple Effect8x8

8x8

Easy

aikoDec 7, 2017 03:00(UTC)
Slitherlink18x10

18x10

Medium

T.KarinoDec 6, 2017 15:00(UTC)
Hashiwokakero22x13

22x13

Hard

-4Dec 6, 2017 15:00(UTC)
Hitori12x12

12x12

Medium

aikoDec 6, 2017 03:00(UTC)
Shikaku10x10

10x10

Medium

Ogawa MinoriDec 6, 2017 03:00(UTC)
Nurikabe 24x14

24x14

Hard

CastyDec 5, 2017 15:00(UTC)
Akari10x10

10x10

Easy

SAKAMOTO, NobuyukiDec 5, 2017 15:00(UTC)

Collection of problems

TypeTotalPlayableUnsolvedOnly openIncompleteSolved
Slitherlink5266000
Nurikabe 5966000
Heyawake 5877000
Akari6688000
Hitori4677000
Masyu5177000
Shikaku5477000
Hashiwokakero6099000
Numberlink4677000
Yajilin4955000
Shakashaka6177000
Satogaeri5477000
Norinori5077000
Kakuro4055000
Sudoku391717000
Ripple Effect4188000

Members who have reached the maximum number of problems can play the "Total" number of problems.