Sudoku Websites

The Internet is partly responsible for the popularity of Sudoku in recent years. Many websites offer daily puzzles in various degrees of difficulty, puzzle collections, background information, solving tips, new variants and places for the Sudoku community to interact with each other.

Online Daily Sudoku Puzzles

Ordinary Sudoku

Daily Puzzles — Sudoku
A new daily Sudoku at four difficulty levels (Easy, Medium, Hard, Expert), with a date-picker archive and clean, ad-free playable interface. Also publishes daily Killer, Mini, and Samurai Sudoku.
YouPlay!
Free puzzle website created by Lovatts Publications, leaders in the field of puzzle production. This site has Sudoku to suit all playing levels, a site-wide chat room and a growing community of Sudoku enthusiasts.
Sudoku.com.au
9 sudoku puzzles daily, all free. A great online player, but the biggest drawcard is the huge active community which is very friendly. They have lots of online helpers, as well as blank printable sheets and a sudoku blog which gives out daily solving tips.
The Daily Nightmare
A daily puzzle from the creator of SudoCue which more than lives upto its name. Not for the faint hearted — as the full arsenal of solving techniques is required. The puzzle's archive dates back to December 2005.
One Trick Pony
A daily puzzle from the creator of SudoCue which requires a good range of solving techniques, plus one advanced step to solve. The puzzle's archive dates back to November 2006.
The Daily Lite
Four new puzzles everyday, from the creator of SudoCue, of four levels of difficulty. Ideal for developing and enhancing solving techniques.
Times Online — Sudoku
The London Times. Two daily puzzles of different levels of difficulty. The most advanced techniques required to solve the hardest (Super Fiendish) Times daily puzzles are X-Wings, Naked Subsets and Hidden Subsets. Upto seven days of archived puzzles. Links to recent Sunday Times puzzles and published Times supplement collections.
Sudoku.org.uk
A daily Mike Mepham puzzle of varying levels of difficulty. The hardest puzzles, the Diabolical and the weekly Extreme, require a wide range of solving techniques. A thirty day puzzle archive. The site also publishes daily Jigsaws and Killers.
Daily Mail (uk) — Sudoku
Two daily puzzles of different levels of difficulty. The most advanced techniques required to solve the hardest (Diabolical) daily puzzles are Naked Subsets and Hidden Subsets. The puzzle archive dates back to 2005 October 8.
Guardian (uk) — Sudoku
A daily puzzle of varying levels of difficulty (Mon to Sat). The most advanced techniques required to solve the hardest (Hard) daily puzzles are Naked Subsets and Hidden Subsets. The puzzle archive dates back to May 2005.
BrainBashers Sudoku
Daily sudokus with six level of difficulty. The list of solving techniques needed for their puzzles are listed here. Solutions to each puzzle includes a walkthrough. The archive dates back to 2005 January 1.
The Daily SuDoku
A daily Sudoku with difficulty varying from easy to very hard. The archive goes back to January 2005. 3 Sudoku Variations are also published daily.
7star Sudoku
Mostly daily symmetrical sudokus which occassionally require the most advanced techniques. The archive dates back to 2006 May 1.

Killer Sudoku

Daily Puzzles — Killer Sudoku
A daily Killer Sudoku with cage-sum constraints. Multiple difficulty levels and a date-picker archive.
YouPlay!
Free puzzle website created by the well respected puzzle publishing company Lovatts. This site has Killer Sudoku (also known as Addoku) to suit all levels of players, a site-wide chat room and a growing community of Sudoku enthusiasts.
Times Online — Sudoku
The London Times. On the same page where the regular Sudoku is published, you will also find a daily Killer Sudoku. Difficulty increases during the week from gentle on Monday to deadly on Friday and Saturday.
Sudoku.org.uk
A daily Mike Mepham Killer Sudoku of varying levels of difficulty, plus a weekly Killer. Compared to other online sources, these Killers are relatively easy. Even the weekly extreme can be solved with a basic set of Killer techniques.
Killer Sudoku
Offers a daily Killer Sudoku puzzle. The difficulty is random throughout the week.
DJAPE Daily Killer
If you don't mind a few book ads, you will certainly enjoy this daily Killer Sudoku. The difficulty ranges from easy to IQ or insane. New puzzles are posted Monday through Friday.
Weekly Assassin
A weekly Killer Sudoku is published each Friday. The puzzles are hand-made and the difficulty may vary, but this is not the place for easy Killers.
Guardian (uk) — Sudoku
This site also offers a Killer Sudoku every Saturday. The first one was published on September 30, 2006. All old puzzles are archived.

Sudoku Variants

Daily Puzzles — Samurai & Mini Sudoku
Daily Samurai Sudoku (5 overlapping grids) and Mini Sudoku (6×6) alongside the regular Sudoku and Killer Sudoku.
YouPlay!
A free puzzle and games website featuring a highly-engaged network of Sudoku enthusiasts. Variants include X Sudoku, Windoku (Hyper Sudoku), JigSaw Sudoku and X Addoku (X Killer Sudoku).
Sudoku Variants and other Number Placements
Contains puzzles of a large number of Sudoku Variants.

Sudoku Combat / Multi-player Sudoku

SudokuShootout
Free AJAX Multiplayer Sudoku, Play against your friends in real-time. iPhone/iPod Touch Compatible!
YouPlay!
Free puzzle website created by the well respected puzzle publishing company Lovatts. Play in Sudoku Tournaments vs players from across the world, or just play vs someone else for fun!

Online Sudoku Puzzle Collections

Ordinary Sudoku

Pure Sudoku — Printable Sudoku Puzzles
A collection of printable sudoku puzzles at 5 difficultly levels.
Sudoku Player's forum
Has many different puzzle collections in the General/Puzzle forum. These are constantly being updated. A good place to start is the Puzzle collections sorted by solving qualities.
SudoCue Downloads
Has 7 download Sudoku files available, for the SudoCue Program. The puzzles collections are aimed at all different levels of playing ability. nb Beginners should start with The Learning Curve Collection.
Web Sudoku
A different puzzle is presented for each log in. It is also an online puzzle generator, where the level of difficulty (four levels) is chosen by user. It appears that the most advanced technique that is required to solve the hardest Web Sudoku puzzles (Evil) are Naked Subsets and Hidden Subsets.
Minimum Sudoku
Contains 36628 distinct starting grids with 17 givens. (Currently, it is believed that at least 17 givens are needed to construct a valid puzzle.)
Sudoku puzzles
Puzzles are divided into eight difficulty levels.
Razzle
Free online/printable sudoku puzzles ranging from easy to expert. Expert level requires X-Wing, XY-Wing, Simple Colouring, and Swordfish techniques to solve.

Directories & Link Indexes

SudokuLinks.com
A curated directory of Sudoku resources — daily-puzzle sites, generators, solvers, blogs, mobile apps, and printable puzzle books — organised by category for quick discovery.

Online Sudoku Solvers

Ordinary Sudoku

Jigsaw Sudoku

See Also