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Privacy policy

Last updated when this page was written. Review before publishing.

The short version

There is no server. This site is a set of static files; the game runs entirely in your browser. We do not have accounts, we do not collect your name or email, and nothing you do in the puzzle is transmitted anywhere.

What is stored, and where

Your browser’s localStorage — on your own device, readable only by this site — holds:

  • the puzzle in progress, your pencil marks, undo history and elapsed time;
  • your theme choice and last difficulty;
  • a count of how many explanations you have used today, and whether the mock subscription flag is set;
  • your answer to the cookie and advertising banner.

If you accept the banner, Google Analytics also sets a cookie of its own. That one is described under Analytics below, and it is the only cookie this site causes to exist.

None of it is sent to us, because there is nowhere to send it. Clearing your browser’s site data for this domain deletes all of it and resets the site completely.

Analytics

We use Google Analytics 4 to count visits and see which pages are read. It records the page you are on, roughly where in the world you are (country and city, worked out from your IP address), and what kind of device and browser you use. It also records four things about the game: that a puzzle was started, that one was finished and how long it took, that an explanation was shown, and that someone ran out of free explanations.

Counting happens whether or not you accept the banner. We would rather be straightforward about that than bury it. What accepting changes is whether anything is stored about you:

  • Before you accept, and if you decline: no cookie is set and no identifier is kept. Each page you open is counted on its own, with nothing tying it to your previous visit or your next one. Google fills the gaps in its reports with estimates rather than with data about you.
  • If you accept: Google sets a cookie so that several visits from this browser count as one returning visitor instead of several new ones. That is the only practical difference.

Either way, none of it identifies you. There is no account, no name, no email and no profile — and nothing about the contents of your puzzle is ever sent. You can change your answer by clearing this site’s data, which resets the banner and deletes the cookie.

One thing we cannot avoid, and will not pretend otherwise: any request to any server reveals your IP address to it, and that includes Google. Google states that it does not log or store individual IP addresses for visitors in the EU, Switzerland and the UK, and uses them only to derive that coarse location before discarding them. Elsewhere its handling is governed by its own policies rather than by us.

Advertising

We intend to show display advertising to keep the site free to play. Ads are served by Google AdSense, which may set cookies and use device identifiers to select and measure ads, including personalised ads.

No advertising script is loaded unless you accept it in the banner. Choosing “Decline” is recorded and respected; the game is identical either way. You can change your mind by clearing this site’s data, which resets the banner.

Once advertising is live, requesting an ad necessarily reveals your IP address and browser details to Google, because that is how any request to any server works. Google’s own handling of that data is governed by its policies, and you can review or limit personalisation through Google’s ad settings.

We publish an ads.txt file at the root of this site. It names the ad networks authorised to sell space here and contains nothing about you; it exists so that advertisers can tell genuine inventory from someone else claiming to be us.

Hosting

The site is served from a content delivery network. Like any web server, the host records standard request logs — IP address, timestamp, user agent — for security and abuse prevention. We do not use those logs to build a profile of you.

Children

The site is suitable for all ages and does not knowingly collect personal information from anyone, of any age.

Your rights

Because we hold no personal data about you on any server, there is nothing for us to export, correct or delete on request — everything is already in your hands, in your browser. If advertising or accounts change that, this page and this section will be updated first.

Contact

Questions about this policy: contact@sudokuzone.app