Daily Sudoku (xoxoxo.live)

Daily Sudoku is the daily puzzle on xoxoxo.live, a small site of free browser games called The Game Room, made by litansh. Its sudoku generator is also on itch.io, where the page points to the daily at xoxoxo.live/daily. There is no sign-up or download, and it works on a phone.

The rules are classic sudoku: fill every row, column and 3x3 box with the digits 1 to 9. Each puzzle is generated with exactly one solution, so there is always something you can deduce. Tapping a digit highlights every copy of it on the board, which makes it easier to see where a number can still go.

The daily puzzle is built from the date in UTC, so everyone gets the same grid, and each one is numbered, counting from #1 on 1 January 2026. A wrong digit is marked straight away and counted as a mistake in its box. When you finish, the game shows your time and mistakes and builds a share block: a 3x3 of the sudoku's boxes, filled where you solved cleanly and marked where you slipped, so it gives nothing away about the puzzle.

Arrows beside the puzzle number take you back through every earlier day to the start, though archive puzzles do not count towards your streak. The page keeps two spaces marked Advertisement for the site's own ad server, which had nothing to show when we played. The same site has the unlimited Sudoku with three difficulties, plus tic-tac-toe, Connect Four, Snake, 2048 and Memory.