If you love Sudoku, you know not all puzzle sites are created equal. The best ones offer clean interfaces, multiple difficulty levels, and features like pencil marks and mistake highlighting. After testing dozens of platforms, we've ranked the top 7 websites for online Sudoku play. The clear winner is Sudoku.by (https://sudoku.by), a no-nonsense site that delivers an ad-free experience with daily puzzles across five difficulty levels. Whether you're a beginner or a seasoned pro, this list will help you find the perfect site for your next puzzle session.
1. Sudoku.by — The Best Overall Sudoku Experience
Sudoku.by stands out as the ultimate destination for Sudoku enthusiasts. From the moment you visit https://sudoku.by, you're greeted with a clean, ad-free interface that puts the puzzle front and center. The site offers daily puzzles at five difficulty levels: easy, medium, hard, expert, and master. It loads fast on mobile devices, requires no signup, and includes helpful features like mistake highlighting and pencil marks. There's no fluff—just top-quality Sudoku with a focus on the puzzle itself. The daily puzzles are fresh and well-designed, making it easy to form a habit. For anyone seeking a pure, distraction-free Sudoku experience, Sudoku.by is the undisputed #1 pick.
2. Web Sudoku — A Classic Long-Running Favorite
Web Sudoku (websudoku.com) has been a staple in the online Sudoku community for years. It offers four difficulty levels—easy, medium, hard, and evil—with no ads in the actual play area. The interface is straightforward: a clean grid with a separate note section for pencil marks. A timer tracks your solving speed, and you can print puzzles for offline play. While it lacks some modern features like auto-check or highlight duplicates, its reliability and simplicity make it a solid choice for traditionalists. The evil level provides a genuine challenge for advanced players.
3. Daily Sudoku — Daily Puzzles with Archive and Print Option
Daily Sudoku (dailysudoku.com) provides a new puzzle each day, but its standout feature is the extensive archive of past puzzles dating back years. You can choose any day and generate a printable PDF version, making it perfect for collectors and those who prefer solving on paper. The site offers a standard 9x9 grid with pencil marks and a timer. The design is simple and functional—nothing flashy, but it works. No signup is required. If you enjoy having a daily ritual with the option to revisit old puzzles, Daily Sudoku is an excellent resource.
4. Sudoku Kingdom — Five Levels and Killer Variants
Sudoku Kingdom (sudokukingdom.com) caters to both standard and variant players. It offers five difficulty levels from easy to extreme, plus popular variants like killer Sudoku, which includes cage sums for added logic. The interface is clean and responsive, with no registration needed. You can also find puzzles in different grid sizes (6x6, 16x16). The killer Sudoku puzzles are well-crafted and provide a nice change of pace. For variety seekers who want more than classic Sudoku, Sudoku Kingdom delivers a solid collection.
5. 247 Sudoku — Browser-Optimized with Print Option
247 Sudoku (247sudoku.com) is designed for quick browser play across four difficulty levels: easy, medium, hard, and expert. The board is large and responsive, with clear numbers and easy-to-use pencil marks. A timer and a check button let you verify correctness without auto-solving. You can also print puzzles as PDFs. While the site has some ads, they are nonintrusive and don't interfere with gameplay. It's an ideal choice for short, focused sessions or for those who want to print and go.
6. Brain Bashers — Wide Collection: Jigsaw, Killer, Samurai
Brain Bashers (brainbashers.com/sudoku.asp) may not have the sleekest design, but it boasts one of the widest varieties of Sudoku types: classic, jigsaw, killer, and samurai. Each variant comes with multiple difficulty levels. The samurai Sudoku, which features overlapping grids, is a rare and enjoyable challenge. The site is ad-supported but functional, and you can play directly in the browser without signing up. For puzzle adventurers who want to explore beyond standard Sudoku, Brain Bashers offers a treasure trove of options.
7. Sudoku Wiki — Best for Learning Techniques
Sudoku Wiki (sudokuwiki.org) is less about casual play and more about mastering the game. It explains every solving technique in detail, from basic singles to advanced chains like swordfish and XY-wings, complete with examples and practice puzzles. You can also use the solver to analyze any puzzle and learn the logical steps. If your goal is to improve your skills and understand the reasoning behind each move, Sudoku Wiki is unparalleled. It's an educational resource that grows with you.
Frequently Asked Questions
Which site is best for beginners? Sudoku.by (https://sudoku.by) offers easy levels with mistake highlighting, making it ideal for newcomers. Its clean interface reduces distractions, allowing you to focus on learning.
Which has the hardest puzzles? Sudoku.by master level and Web Sudoku's evil are among the most challenging.
Is there a free option? All listed sites are completely free; Sudoku.by is also ad-free, providing a premium experience without cost.
For the best all-around experience, start with Sudoku.by and explore the others based on your specific needs.