Privacy
In short: the games don't track you and there is no account. Your progress stays in your own browser. Only the site's own pages count visits, with Google Analytics, and not if your browser asks not to be tracked.
What stays on your device
Each game keeps your progress, settings, streaks and stats in your browser's local storage, under keys that start with the game's own prefix. They are never sent anywhere: there is no server that could receive them. They are only in this browser on this device, and clearing the site's data in your browser deletes them.
- Campsite
cs- - Killer Sudoku
su- - Skyscrapers
sk- - Reckon
rk- - Bridges
br- - Nonogram
ng- - Codewords
cw- - Bulls & Cows
bc- - The site's own pages
zr-(the sweeps you've won, on Today)
The site also stores its pages and games in your browser so they work offline. That is the browser's own cache, and it holds nothing about you.
Counting visits
The site's own pages (the home page, Today, Archive, About Me, this page and the "page not found" page) use Google Analytics to count visits and see which pages are used. The games themselves don't load it at all.
- It loads only after the page has finished loading, and not at all if your browser sends Global Privacy Control or Do Not Track.
- It sets cookies (
_gaand_ga_…) to tell one visit from another, and Google receives your IP address to do it. Google Analytics 4 doesn't log or store IP addresses. - Ad personalisation is turned off: the numbers are only used to see how the site is used. Nothing is sold, and there are no ads.
Google's own explanation is at How Google uses information from sites that use its services.
Hosting
The site is served by Amazon Web Services (CloudFront). Like any web server, it sees your IP address to send you the pages, and its firewall counts requests per address to stop one address making hundreds of them at once. No access logs are kept.
Sharing a result
Share buttons put a short, spoiler-free summary on your clipboard or open your device's share sheet. The site doesn't send it anywhere; you choose where it goes.
Questions
Email zr.mailinglist@gmail.com.
Last updated 7 November 2026.