Last updated: 27 September 2026
The short version first — the full details are in the sections below.
Comments you choose to post, emails you send, and anonymous page statistics.
Playgrounds, quizzes and calculators run in your browser; settings are stored only on your device.
No selling, renting or trading of personal information — ever.
You can read everything and download files without signing up.
1. Information we collect
- Comments: name, email and comment text. Your email is never shown publicly.
- Messages: anything you send to [email protected].
- Usage data: pages visited, browser and device type, collected in aggregate.
- Server logs: IP address and request details kept for security for a limited time.
2. Cookies and local storage
The site uses a small number of cookies to remember preferences and measure traffic. Interactive tools (quiz scores, wishlist of facts, shortcut best score) use your browser’s local storage — that data never leaves your device and you can clear it any time in your browser settings.
3. Advertising
Some pages may show ads served by Google. Google and its partners use cookies to serve ads based on your visits to this and other sites. You can opt out of personalised advertising at Google Ads Settings or aboutads.info. Read how Google uses information from sites that use its services.
4. Downloads
Practice files are served directly from this site. Downloading them does not require any personal information.
5. Third-party services
Pages may load fonts, code libraries or project data from services such as Google Fonts, Cloudflare, cdnjs and GitHub. These services receive your IP address as part of normal web requests and have their own privacy policies.
6. How long we keep data
Comments stay until you ask for removal. Emails are kept as long as needed to answer them. Server logs are rotated regularly.
7. Your rights
You can ask to see, correct or delete your personal data — email [email protected]. We will respond within 30 days.
8. Children
This site is not directed at children under 13 and does not knowingly collect their data.
9. Changes to this policy
When this policy changes, the “Last updated” date at the top changes too.