Privacy
Short version: the calculators run entirely in your browser, and the numbers you type never leave your device.
What you type
Every calculation, including the heavy ones handed to a background Web Worker, happens on your own device. The site has no server code, no accounts and no forms that submit anywhere. Numbers you enter are not uploaded, logged or shared.
What is stored on your device
Only one thing: if you pick light or dark with the theme button, that choice is saved in your browser's local storage under the key primeorchard-theme, so the next page opens in the same theme. Choosing "Auto" removes it. You can also clear it at any time by clearing this site's data in your browser settings. The site does not use cookies.
Analytics
The site is hosted on Cloudflare, which adds Cloudflare Web Analytics to every page. It counts page views without cookies and without cross-site tracking, and it never receives what you type into the calculators. Cloudflare, like any web host, also handles the ordinary request data (such as your IP address) needed to deliver the pages; see Cloudflare's privacy policy.
Links to other sites
Pages link to sources such as the OEIS and Wikipedia, to sister sites, and to two recommended services, CleanTempMail and WebTraceCheck. Those sites have their own privacy policies; nothing is passed to them unless you follow a link.