How the Daily Challenge works

One puzzle a day, the same for everybody, generated from the date itself.

Each day brings a fresh puzzle. Everyone opening the page on the same day gets exactly the same one, which makes it something you can compare with a friend without anything being stored.

How it can be the same for everyone with no server

The puzzle is generated from a seed derived from the date, the engine, and a version number. Given the same seed, the generator produces the same puzzle — so your browser and everybody else's independently arrive at an identical grid without any coordination.

Nothing is downloaded and nothing is recorded. The date is the only input.

No streaks, no accounts, no leaderboard

There is deliberately nothing to lose by missing a day. Streak counters are a retention mechanic — they work by making you feel bad about stopping, and that is not a relationship worth building with a puzzle page.

There is no account, no username, no leaderboard and no tracking of whether you finished. If you want to compare with someone, tell them your time.

Yesterday's puzzle

Previous days remain reachable, since they are derived from their dates in the same way. A missed day is not gone.

Whose today?

A puzzle chosen by the date raises a question the date alone does not answer: which midnight. These use your device's local date, which means the puzzle changes at midnight where you are — and two people in different time zones are genuinely on different puzzles for part of every day.

Someone in Manila gets tomorrow's several hours before someone in London, and if they compare notes during that window they are discussing different grids. Neither is early or late; both are on the puzzle for their own date. The alternative would be to pick one time zone and impose it globally, which fixes the comparison and means the puzzle changes at some arbitrary hour of the afternoon for most of the world. Local midnight is the less surprising of the two.

Tomorrow's puzzle is not a secret

Because the seed is derived from the date by a rule that runs on your own machine, anybody can work out any day's puzzle in advance — change the system clock and it appears. That is not an oversight or something to be defended against.

Keeping future puzzles hidden would require the answer to live somewhere you cannot reach, which means a server, an account, and a request every time you play. All three are things these tools deliberately do not have. And the protection would be guarding nothing: with no scores, no streaks and no leaderboard, there is no advantage to be gained by seeing tomorrow's early. The puzzle is the same for everyone on the same date because the rule is public, not because it is enforced — which is also why it keeps working with no connection at all.

Frequently asked questions

Is everyone's puzzle the same?

Yes, for a given date. The seed comes from the date, the engine and a version number, so every browser generates the identical puzzle independently.

Is my progress saved?

No. There is no account, no streak and no record of whether you finished. Refreshing the page starts the same puzzle over.

Can I do an earlier day?

Yes. Past days are derived from their dates the same way and remain available.