Your birth data stays on your device.
The short version: when you calculate a chart, the math runs in your browser and your birth date, time, and place are never sent to us. Accounts and the weekly email are optional, off by default, and easy to leave. We show no ads and use no cross-site tracking.
What happens when you use a calculator
Every chart on this site is computed on your own device. When you enter a birth date, time, and place, that information is used by code running in your browser to calculate the chart. It is not transmitted to our servers, logged, or stored by us. This is a deliberate design choice, described in full on our methodology page.
Place search uses a list of cities that ships with the site and runs entirely in your browser. Typing a city name does not call an external service.
Charts you save
When you save a chart, it is stored in your browser's local storage — on your device, under your control. It is not sent anywhere unless you choose to create an account (below). Clearing your browser's site data removes saved charts. We cannot see them and cannot recover them for you.
Optional account (sync across devices)
You can create a free account to keep your saved charts on more than one device. This is entirely optional and the tools work fully without it. If you create one:
- You sign in with a one-time link sent to your email address — there is no password to store.
- We store your email address and the charts you choose to sync (which include the birth details for those charts) with our database provider, Supabase, so they can appear on your other devices. Access is restricted to your own account.
- While you are signed in, a sign-in token is kept in your browser so you stay logged in. Signing out removes it.
- You can delete your account and its stored charts at any time by emailing hello@zodiacs.org.
Optional weekly email
Account holders can opt in to a weekly email summarizing the coming week's sky for their saved charts. It is unchecked by default. If you opt in, we store that preference and send the email through our email provider, Resend. Every email includes a one-click unsubscribe link, and you can turn it off from your profile at any time. We do not use your email for anything else and we do not sell or share it.
Hosting, logs, and analytics
The site is hosted on Vercel. Like all web hosts, their servers process the requests your browser makes and may keep short-lived technical logs (such as IP address and browser type) to deliver the site and guard against abuse. We do not run advertising, and we use no cross-site tracking cookies or third-party marketing pixels. If we ever add usage analytics, it will be a privacy-friendly, cookieless kind, and this page will say so.
Cookies
We do not use advertising or tracking cookies. The only browser storage we rely on is local storage for your saved charts and, if you sign in, a first-party sign-in token — both on your device, neither used to track you elsewhere.
Children
The site is intended for a general audience and is not directed at children under 13. We do not knowingly collect personal information from them.
Your choices
- Use every calculator with no account and nothing stored off-device.
- Delete saved charts by clearing your browser's data for this site.
- Delete an account and its synced data by emailing us.
- Turn the weekly email off with one click, any time.
Changes
If we change how we handle data, we will update this page and its date. Material changes to the account or email features will be reflected here before they take effect.
Contact
Questions about privacy, or a request to delete your data, go tohello@zodiacs.org.
Last updated: 8 July 2026