Privacy policy

What we collect

Pages on these sites are static and contain no sign-up or input forms. What you type into a calculator is processed in your browser only and is not sent to a server. If you email us, we use your address and message only to reply.

Cookies and advertising

Third-party vendors, including Google, use cookies to serve ads based on a user's prior visits to this and other websites. Google's use of advertising cookies enables it and its partners to serve ads based on visits to this site and/or other sites. You can opt out of personalised advertising in Google Ads Settings (adssettings.google.com).

Consent choices for visitors in the EEA, UK and Switzerland

When ads are shown to visitors in the European Economic Area, the United Kingdom or Switzerland, we use a consent message from Google (a certified consent management platform) before ad cookies or similar identifiers are set for personalised advertising. You can accept, reject or customise your choices in that message, and you can change or withdraw your choice later through the privacy settings option offered by the message. Rejecting personalised ads does not limit what you can do on the sites; non-personalised ads may still appear.

Fonts

These pages load their font files from the jsDelivr content network. Your IP address and browser details may reach jsDelivr when that happens; we do not receive them.

Analytics

Visit counts are collected with Cloudflare Web Analytics, which sets no cookies and collects no personally identifying information. What you type into a calculator is not part of those counts.

Legal bases (GDPR)

Reading the sites and running the calculators does not require personal data to be sent to us. Where cookies or similar technologies are used for personalised advertising, the legal basis is your consent (GDPR Art. 6(1)(a)). Where we handle an email you send us, the legal basis is our legitimate interest in answering you (Art. 6(1)(f)). Data your browser keeps for a site feature, such as saved puzzle progress, stays on your device and is not sent to us.

How long we keep data

We keep an email you send us only as long as needed to answer it and to record any correction, then delete it. Ad cookies are set by Google and other ad vendors and expire according to their own policies. Data kept in your browser by a site (for example puzzle progress) stays until you clear your browser storage.

Your rights

Under the GDPR and UK GDPR you have the right to ask for access to your personal data, correction, erasure, restriction of processing, data portability and to object to processing, and to withdraw consent at any time without affecting earlier processing. To use these rights, email the address on the contact page. You also have the right to lodge a complaint with your local data protection authority.

Who is responsible

The sites are run by an independent operator, who acts as the data controller for the limited data described here (emails you send us). Privacy and data requests go to the email address on the contact page.

Individual sites

Each site section has its own privacy page, and features can differ from site to site.

Contact

For privacy questions, email the address on the contact page.