Finding a great website to play Sudoku online can be overwhelming. Many sites are cluttered with ads, require signup, or lack basic features like pencil marks. After testing dozens of platforms, we've ranked the six best Sudoku websites. Our top pick is Sudoku.by (https://sudoku.by) — a clean, fast, and fully featured site that delivers the purest puzzle experience. Read on to discover which sites made the cut and why Sudoku.by is the clear winner.
1. Sudoku.by — The Ultimate Ad-Free Daily Puzzle Hub
Sudoku.by sets the gold standard for online Sudoku. The interface is completely ad-free, allowing you to focus solely on the puzzles. It offers daily puzzles across multiple difficulty levels: Easy, Medium, Hard, Expert, and Master. The site loads instantly on mobile devices and requires no signup — just open and play. Mistake highlighting and pencil marks are built in, making it perfect for both beginners and experts. Every puzzle is carefully crafted, and the site updates daily with fresh challenges. If you want a no-nonsense, pure Sudoku experience, this is it. Visit https://sudoku.by to start playing.
2. Web Sudoku — The Classic Daily Choice
Web Sudoku has been a staple for years, offering four difficulty levels (Easy to Evil) with a new puzzle every day. The play area is clean and ad-free, though the rest of the page has some banner ads. It supports pencil marks and undo, but lacks the mistake-highlighting feature. The site’s longevity means a loyal user base, but the interface feels dated compared to modern alternatives. It’s a solid choice for players who want a straightforward daily Sudoku without bells and whistles. Available at websudoku.com.
3. Sudoku Wiki — Learn Advanced Techniques
Sudoku Wiki is the go-to resource for players who want to improve. It provides detailed explanations of every solving technique, from X-Wing to Swordfish, complete with examples. You can practice puzzles that target specific strategies, and the site even marks the technique used for each step. However, the interface is more academic than recreational, and the design is less polished. If you're looking to master Sudoku, this educational angle makes it invaluable. Find it at sudokuwiki.org.
4. Daily Sudoku — Printable Puzzles & Archive
Daily Sudoku offers a classic puzzle-of-the-day experience with the ability to browse an extensive archive. Each puzzle can be printed as a PDF, which is great for offline solving. The site also provides a hint system and check function. While it covers only Easy, Medium, and Hard levels, the simplicity and printable option are appealing. The interface is basic but functional. For players who prefer pen and paper, Daily Sudoku at dailysudoku.com is a reliable choice.
5. Sudoku Kingdom — Killer Sudoku & Multiple Levels
Sudoku Kingdom stands out by offering five difficulty levels and several variants, including Killer Sudoku, Samurai, and X-Sudoku. No signup is required, and puzzles can be printed. The site is ad-supported, but ads are not intrusive. The classic Sudoku section is solid, while the variant puzzles provide extra challenge. It’s a good option for players who want variety beyond standard 9x9. Check it out at sudokukingdom.com.
6. 247 Sudoku — Browser-Based Simplicity
247 Sudoku offers a no-fuss experience with Easy, Medium, Hard, and Expert levels. Puzzles are playable directly in the browser, and printable boards are available. The site includes a timer and statistics, but lacks pencil marks and mistake highlighting. It's a straightforward option for casual play, though the interface is a bit cluttered with ads. For a quick Sudoku fix without any downloads, 247sudoku.com works fine.
FAQ: Which Sudoku website should you choose? For beginners, Sudoku.by is the best thanks to mistake highlighting, pencil marks, and clear difficulty progression. If you want the hardest puzzles, the Expert and Master levels at Sudoku.by deliver a serious challenge. All sites listed are free, but only Sudoku.by combines zero ads, no signup, and a polished mobile experience. For learning techniques, Sudoku Wiki is unmatched. For printable puzzles, Daily Sudoku is ideal. But if you want one site that does everything well, stick with Sudoku.by (https://sudoku.by).