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
- Sudoku Center Online
- 9 sudoku puzzles of 5 different levels. You can find Sudoku Solver too.
- 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.
- 3 clasic sudoku puzzles and one nonconsecutive sudoku puzzle daily and many sudoku variants, everything online and with many scoreboards and statistics. (Slovak and English versions)
- 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.
- 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 Unlimited (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.
- Daily sudokus by Gaby Vanhegan with six levels of difficulty. The hardest puzzles have at least Nightmare standard. The archive goes back to 2005 October 10.
- 7star Sudoku
- Mostly daily symmetrical sudokus which occassionally require the most advanced techniques. The archive dates back to 2006 May 1.
- Online Picture Sudoku
- Sudoku puzzles with pictures (numbers also available) playable online and generated at random each time the page is loaded. All can be solved with more simple techniques, and have only one solution. You can put Sudoku on your own site with your own pictures.
- Free Sudoku Games
- Play free sudoku games online or just download the pdf containing the puzzle and play offline.
- Kodden's Daily Sudoku
- A new sudoku puzzle every day and randomly generated puzzles of various difficulty.
- Sudoku puzzles for beginners
- Free on-line Sudoku game that offers assistance in finding the correct solution. Solve one of the included puzzles or enter your own.
- 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.
- 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 Unlimited (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.
- 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 Combat / Multi-player Sudoku
- Free AJAX Multiplayer Sudoku, Play against your friends in real-time. iPhone/iPod Touch Compatible!
- 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
- 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.
- Sudoku Assistenten forum - Share sudokus
- A collection of interesting and difficult puzzles posted by the forum's members.
- 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.
- Color coded sudoku puzzles
- Free online color coded sudoku puzzle solver with timer, pencil, graph, hints, multiple difficulty level etc
- Free online/printable sudoku puzzles ranging from easy to expert. Expert level requires X-Wing, XY-Wing, Simple Colouring, and Swordfish techniques to solve.
Online Sudoku Solvers
- SudokuSolver.co.nr by Dany Gunawan
- Play Sudoku by Stefano Chermaz
- Colorcoded Sudoku Solver by Deepan Chakravarthy
- Scanraid Sudoku Solver by Andrew Stuart
- Sudoku @ PaulsPages by Paul Stephens
- Sudoku Assistant by Bob Hanson
- Su Doku Solver by Rubylips
- Sudoku Explainer by Nicolas Juillerat
- SudokuPower by Arnold Kamminga & Hans Schoorlemmer
- Free Sudoku Solver
- Scanraid Jigsaw Sudoku Solver by Andrew Stuart