One sudoku a day, the same board for everyone
No account, no server, no list of puzzles to run out. The date is the seed, so a link to any day keeps opening that day's board — next month and next year alike.
Most "daily puzzle" pages need a database behind them: someone generates the boards, stores them, and hopes nothing expires. This one does not. The date is fed into the same generator the game uses, and the same date always produces the same board — on your phone, on a laptop, in a different country, three years from now.
That makes the daily puzzle the simplest thing on the site: one URL, one board, one setting picked by the day of the week. It also makes it shareable without a server — send someone a date and they get the puzzle you solved, not whichever one happens to be up today.
Answer
Spoilers — open this only after you have finished.
How the date picks the board
The generator starts from the date string (2026-11-08), turns it into a fixed random seed, and builds a full grid. Then it digs holes and rates what came out with the same technique engine used everywhere else on this site. Nothing is stored: close the tab, come back next week, and the board is recomputed identically.
The setting is not random either. It follows the week so the week builds up instead of jumping between a singles drill and a chain puzzle on consecutive mornings:
| Day | Setting | What it usually asks for |
|---|---|---|
| Monday, Tuesday | Easy | singles only |
| Wednesday, Thursday | Medium | pairs and box-line |
| Friday | Hard | X-Wing and the skyscraper family |
| Saturday | Expert | chains and swordfish |
| Sunday | Master | a board the sixteen techniques cannot finish |
"Master" here has a precise meaning: the grading engine could not reason its way to the end. It does not mean "impossible" — it means you will need a guess, a chain you build by hand, or a technique this engine does not implement. The census page has the measured counts behind that distinction.
Why one shared board is worth doing
A puzzle you can discuss is a different object from a puzzle you simply complete. If two people open the same date, they can argue about the same cell, and a hint that names a technique lands on the same position. That is also why the technique guides exist: the useful question after a daily board is rarely "what number goes here", it is "what should I have looked for".
The scoreboard is local to your device — there is no account and no global ranking. The sharing here is a link between people, not a leaderboard.
Dates that stay valid
The board is a function of the date, so ?d=2026-11-08 is a permanent address for that day's puzzle. An old link does not turn into a new puzzle when midnight passes, and it does not 404 when tomorrow's board replaces today's on the front page. The archive lists the last fourteen days with the setting and clue count each one actually produced.
If you would rather play a free board at a setting you choose, the game does that. If you want paper, the printable sheets make one, two or four per A4 page, and if you have a puzzle from somewhere else, the solver explains each step in plain words instead of just filling the grid.