KnowYourBaZi
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Privacy Policy

Last updated: October 8, 2026

Thank you for using KnowYourBaZi ("the Site"). This policy explains who collects data, what data is collected and why, how long it is kept, where it is stored, the legal basis for handling it and what rights you have. It also explains how third-party advertising and cookies work.

1. Who collects your data

The Site is run independently by an individual, the author who writes as Haiyuan (海淵), not by a company or organization. "The Site", "we" and "us" in this policy refer to that operator. For any question or request about your personal data, please email the address listed under "Contact us" at the end of this page.

2. How your chart data is handled (guest mode)

The Site's BaZi charts, Five Elements analysis, Luck Pillars and annual cycles, and reading content are all calculated locally in your browser. When you use the Site as a guest, the birth date, birth hour, name and other details you enter are not uploaded and are not stored by the Site. You decide for yourself whether to save the results on your own device (in your browser's local storage).

The only thing sent to our server when you cast a chart is an anonymous chart count: when you press "Calculate my chart" or "Generate my reading", the Site only tells the server "add one to the total". It does not include your birth date, birth hour, gender, name or any information that could identify you. Recasting the same chart during the same visit is not counted again; this check happens only in your browser. To stop people from inflating the number, an IP code is written to a rate-limit record when the count is sent. The code is a salted hash of your IP address; the salt is a secret key that is not published, the code changes every day, and the record is deleted after one day. The "N charts cast here so far" figure shown on the home page is this total.

The Site also records a few anonymous usage counts, such as how many times a chart was cast, the end of the basic reading was reached, a tool was opened or the newsletter was joined, so we can see which features are used. Only the event name, the page language, the section of the Site and the page type are sent (events about a form also carry the form's code name, such as the solar-term lookup form; a "page not found" event carries the kind of referrer, such as a search engine or a link on this Site), and the server only adds up counts by date. No IP address, cookie or identifying data is stored, and there is no visitor ID, so we can see daily totals but not what any one person did. Inflation is prevented with the rate-limit record described above. Visits identified as crawlers or automated browsers are not counted.

After casting a chart on the home page you may choose to remember this birth data on this device. Only if you press that button is the birth data kept in your browser so it can be filled in on your next visit. It is never uploaded, and you can remove it at any time with "Forget it" or by clearing your browser data. If you do not press the button, nothing is kept.

3. Member accounts and birth data (optional)

Signing up as a member is entirely voluntary. If you do not sign up, the Site stays in the "nothing stored" guest mode described above. When you choose to sign up or log in with a third-party account, the Site stores the following data, used to fill in your chart automatically the next time you log in, so you do not have to enter it again, and to keep you logged in and your account secure:

If you sign up with an email address, you must click the link in a verification email before you can log in. Verification emails and password reset emails are sent through Google's Gmail service, and your email address and the message content pass through Google's servers when they are sent (Google's privacy policy applies). The member data above is stored on the Cloudflare infrastructure the Site uses. You can log in at any time to change your birth data, or delete your account yourself as described in the next section.

4. Deleting your account

Members can delete their own account: log in, open the "My birth data" panel, and use "Delete account" at the bottom. Your account, birth data, saved charts and login sessions are then deleted together immediately and cannot be recovered.

5. Newsletter subscription (optional)

If you leave your email address on the Site to subscribe to the newsletter, the Site stores only your email address, your chosen language, the page you subscribed from, the times you subscribed, confirmed and unsubscribed, and an optional Day Master stem (such as "Jia", used only to pick which sections of the email to send you; it can be left blank, and no birth date or other chart data is collected). This is used only to send you the Site's new articles and monthly highlights. After you submit the form we first send a confirmation email, and sending only starts after you press the confirm button in it; this stops others from signing up your address without permission. Email addresses that are not confirmed are deleted 7 days after the confirmation email is sent (if the confirmation email is still queued because the daily sending limit was reached, the 7 days start once it is sent). Confirmation emails and newsletters are currently sent through Google's Gmail service, and your email address and the message content pass through Google's servers when they are sent (Google's privacy policy applies). To prevent abuse of the form, an IP code is written to a rate-limit record when you submit it, in the same way as in section 2: salted and hashed, changed every day, and deleted after one day. The subscriber list is not linked to your birth date, your chart or your member account, and it is not sold or given to third-party advertisers. Every email includes an unsubscribe link, and after you unsubscribe we stop sending emails. The whole record is deleted 30 days after you unsubscribe. If you want it deleted sooner, just email us.

6. Data we may collect automatically

As with most websites, when you visit, the host and related services may automatically record technical data such as your IP address, browser and device type, time of visit and the pages you view. This data is used for operations, security and traffic analysis, and is not used to identify you personally.

7. Cookies and similar technologies

The Site and third-party services may use cookies or similar technologies to keep members logged in, remember your preferences, analyze traffic and show ads. You can manage or delete cookies in your browser settings; disabling some cookies may affect your experience of the Site.

In addition, the Site stores the date of your last visit in your browser's local storage (localStorage). It is used only to measure the share of returning visitors: at most once a day, an anonymous "new visitor" or "returning visitor" count is sent. The date itself is never uploaded, and it is not a cookie; clearing your browser data removes it.

8. Third-party advertising (Google AdSense)

If you are in the EU, the UK or similar regions, the Site asks for your consent to personalized ads through a Google-certified consent tool; you can change your choice at any time through that tool.

9. Analytics

The Site uses Cloudflare Web Analytics to understand overall traffic, such as which pages are viewed most, where visitors come from, which browsers and device types they use, and their approximate country. This service does not use cookies and does not track individual visitors across sites. What it collects is aggregate statistics only, and it is not used to identify who you are. For how Cloudflare handles this data, see the Cloudflare Privacy Policy. If we switch to or add another analytics tool in the future (for example, Google Analytics), we will update this section before turning it on.

The Site's own anonymous usage counts (see section 2) also cover site search: opening the search box and clicking a result are each counted once. When a search finds no pages at all, the keyword you typed is sent to the server with its digits (and date words right after them) removed and cut to the first 12 characters, so we can see what content is missing. Keywords from searches that find results are not recorded, and anything containing "@" is not sent at all. These keywords are only counted by date and language, are not linked to any other data, and are deleted after 30 days; our reports list only keywords that come up at least 3 times within 30 days. Please do not type personal information into the site search.

10. How long data is kept

11. Where data is processed and international transfers

The Site's data is stored on Cloudflare's global network and databases; emails are sent through Google's Gmail service; ads are provided by Google AdSense. The servers of these services may be located outside your country or region, so your data may be processed abroad.

12. Legal basis for processing (readers in the EU and UK)

If you are in the EU or the UK, the Site relies on the following legal bases:

13. Minors' data

Under Taiwan's Civil Code, anyone under 18 is a minor. The Site's services are not directed at children. A user under 18 who wants to sign up as a member, save charts or subscribe to the newsletter should first have a legal guardian (a parent or guardian) read and agree to the Terms of Use and this policy; for children under 7, the legal guardian should use the Site on their behalf. Under Taiwan's Personal Data Protection Act, a legal guardian may email us to look up, correct or ask us to delete a minor's data, and if we learn that we hold a minor's data without a legal guardian's consent, we will delete it once this is confirmed. Tools such as Children's Charts are often used by parents who enter their child's birth data. That data is calculated only in the browser and is not uploaded, unless you are a member and choose to save the chart yourself.

14. Your rights

If you use the Site only as a guest, the Site does not store the data you enter for your chart, so in most cases we hold no personal data about you that could be looked up or deleted.

Under Taiwan's Personal Data Protection Act, you may ask, regarding the personal data the Site holds about you, to look it up or review it, to receive a copy, to supplement or correct it, to stop its collection, processing or use, and to have it deleted. If you are in the EU or the UK, you also have the right to data portability, and you may lodge a complaint with the data protection authority where you live.

Members can log in at any time to change their birth data, or delete their account themselves as described in section 4; for other requests, please email us. Signing up and subscribing are voluntary: without an email address you cannot become a member or receive the newsletter, but you can still cast charts and read the Site.

15. Changes to this policy

This policy may be updated as our services or the law change. The latest version is the one on this page, and the date of the update is shown at the top of the page.

16. Contact us

If you have any questions or requests about this policy or your personal data, please contact: [email protected]