📰 Daily Sudoku
A new puzzle every day. Same puzzle for everyone worldwide. Resets at midnight.
About This Game
Sudoku is constraint satisfaction, not arithmetic. The digits are only symbols and could be nine colours without changing anything. What the puzzle actually trains is systematic elimination and the discipline of proving a placement rather than assuming it.
Sudoku specifically appears in the research. The PROTECT study, led by the University of Exeter with King's College London, assessed 19,078 adults aged 50 and over and found that those doing number puzzles more frequently performed better on attention and reasoning tests. It is an observed association, so it does not establish that sudoku caused the difference.
Completing a medium grid with no guesses is the benchmark that matters. Time is secondary to never placing an unproven digit.
The tip most people miss: scan by number, not by square. Most players stare at an empty cell asking what fits. Faster solvers pick one digit, then sweep every row, column and box asking where that digit must go. The same information arrives far quicker from the second angle.
How to Play Sudoku
Fill every row, column, and 3x3 box with the numbers 1 through 9. Each number must appear exactly once in each row, column, and box. The puzzle starts with some numbers given. Use those to figure out the rest through logical elimination.
Basic strategy: Look for rows, columns, or boxes where only one number can possibly fit. This is called a "naked single." For harder puzzles, look for a number that can only go in one cell within a row, column, or box, even if other numbers could also fit there. This is a "hidden single."
The puzzle resets every day at midnight and is the same for all visitors worldwide on that date. Come back tomorrow for a fresh challenge.
New to Sudoku or want to improve? Read How to Play Sudoku: Rules, Strategies, and Tips for Every Level for a complete guide from beginner to advanced techniques.