Daily Sudoku

Sudoku needs little introduction: a 9x9 grid split into nine 3x3 boxes, some cells given, the rest blank. Each row, each column and each box must end up with every digit from 1 to 9 exactly once. You find the missing digits by elimination, never by arithmetic, so it is a logic puzzle that happens to use numbers.

Puzzle-sudoku.com keeps graded 9x9 grids from Basic to Evil, plus 12x12 and 16x16 versions, Killer and Jigsaw sudoku, and a Daily Sandwich Sudoku. The Special Daily Sudoku is its standard daily: one 9x9 grid, the same for everyone that day, with the date on the page and a list of recent dates beside it. Settings cover pencil notes, highlighting duplicates and same numbers, a night mode and a timer you can hide. The site shows banner ads beside the board; becoming a patron removes them and lets you go back through the last 30 daily puzzles. A Hall of Fame lists solving times, and the site's screens come in English and about twenty other languages, from German and French to Japanese and Korean.

It fits a daily routine for anyone who already likes sudoku and wants one fixed grid a day instead of picking a difficulty. Players who find it quick can move on to the weekly and monthly specials or to the Killer and Jigsaw variants on the same site.