Sudoku Zen — Classic Sudoku

Find your focus. Sudoku Zen is classic sudoku with everything you need and nothing that gets in the way — a clean rice-paper board, gentle colors, and puzzles generated fresh every time, each one guaranteed to have exactly one solution. FOUR DIFFICULTIES From Easy (pure logic, no guessing) to Insane (for true masters only). Every puzzle is graded by how much real deduction it takes, so Medium always feels like Medium. DAILY CHALLENGE One new puzzle every day, the same for everyone. The difficulty changes from day to day and peaks on Saturday. Solve each day to build your streak. SMART HELP WHEN YOU WANT IT • Notes with automatic cleanup — placing a number clears matching pencil marks nearby • Nudge highlights a nearly finished row, column, or box when you're stuck • Hints that explain themselves • Undo, mistake highlighting, and a same-number highlighter you can toggle EARN YOUR STARS Finish clean — no mistakes, no hints — for a five-star rating. Track best times, completion rates, and build a daily streak on the stats page. MAKE IT YOURS Play in Zen, a calm paper-and-ink theme, or choose from five more — Midnight, Sakura, Newsprint, Ocean and Ember. Try any of them free for 24 hours by watching a short ad. ONE PURCHASE, NO ADS FOREVER A single Remove Ads purchase takes away every banner and full-screen ad and unlocks every theme, forever, on all your devices. No account. No energy meters. No daily paywalls. Just sudoku, done right.