The short version
You can play every puzzle on this site without giving us anything. We store what you played so your streak survives closing the tab. We do not sell anything about you, and there is nothing here we would not be comfortable showing you — which is why you can download all of it in one file.
Playing without an account
On your first visit we place one cookie holding a random identifier, and create a matching record on our server. It contains no name, no email address and no location. It exists so that your progress and your streak are not lost when your browser clears its storage — which phones do routinely, and which is why this is a server record rather than something kept only in your browser.
If you do not come back, that record and everything attached to it is deleted automatically after 180 days.
If you create an account
Your email address, a hash of your password, and your timezone. The hash is one-way: we cannot read your password, and neither can anyone who obtains the database.
Your timezone is there for one reason — your streak is counted against your own calendar day, so that someone in California and someone in Delhi each keep a streak by playing on their own Tuesday.
If you sign in with Google, we receive your email address and Google’s own identifier for you. We ask Google for nothing else: no contacts, no calendar, no profile beyond the address.
What we record while you play
Which puzzles you opened and finished, how long each took, mistakes, hints, and your streak. Also the moves you made — the digits typed into a Sudoku, the words guessed, the directions swiped.
The moves are kept because the server replays them to work out your real result rather than trusting what your browser reports. It is the only way a score means anything. They are not read by a person and they are included in your data export like everything else.
Notifications
Only if you ask for them, and we only ask after you have built up a streak worth protecting. If you agree, we store the address your browser gives us for delivering notifications, and the hour you chose.
At most one a day, never on a day you have already played, and you can turn them off from your account page without losing anything else.
Analytics
We count things on our own servers: pages viewed, puzzles started and finished, streaks extended and broken. These are attached to the same identifier described above.
There is no third-party analytics script on this site. Nothing about your visit is sent to an analytics company.
Advertising
There is no advertising on this site at the moment, and no advertising script is loaded. When that changes this section will name the provider before anything is served.
There is never an advertisement on the screen shown when you finish a puzzle. That is a deliberate rule in the code, not an oversight.
Your data, in one file
If you have an account you can download everything we hold as a single JSON file. Everything means everything: your results, your move log, your sign-in history, the emails we sent you, and the analytics events. No part of it is held back and there is nothing to request by email.
You can also delete your account. That is a real deletion — the records are removed, not flagged, and not kept for a cooling-off period. There is nothing to restore afterwards.
Who else sees any of this
Nobody. We do not sell, rent or share your data. The only third parties involved at all are the ones needed to make the site work: our hosting provider, Google if you choose to sign in with it, and your browser’s push service if you ask for notifications.
Children
Accounts are for people aged 13 and over. The puzzles themselves are suitable for anyone; the account is the part with an age on it.
Asking us anything
Get in touch. If you want something removed and cannot use the buttons above, say so and we will do it.