Privacy Policy

Last Updated: September 27, 2026

Your privacy is important to us. This Privacy Policy explains what information we collect, how we use it, and your choices.

In short: there are no accounts, so we never ask who you are. Your hands, settings and progress are saved in your own browser, not on our servers, and our server keeps no record of the tiles you send it.

1. Information We Collect

1.1. Information You Provide

• The tiles you enter. Some of our tools send your tiles to our server to be checked against the card; others do the checking in your browser. Either way, the server sends back the result and keeps no record of your tiles.
• Photos of your tiles, if you use the Photo button (see 1.3).
• Messages you email us. If you contact us, we receive your email address and whatever you include in your message.

1.2. Information Saved on Your Device

Your current hand, the card year you chose, your display settings and the patterns you have marked as mastered are saved in your browser's local storage, so they are still there next time. This information stays on your device and is not sent to us. Clearing your browser's data for this site removes it.

1.3. Photos of Your Tiles

The Hand Analyzer's Photo button reads your hand from a photo of your rack. Using it is optional; you can always enter your tiles by tapping them instead. If you use it:

• Before the photo leaves your device, your browser shrinks it and saves it as a new image. This removes the details a camera attaches to a photo, such as where and on what device it was taken.
• The photo is sent to our server, which passes it to Anthropic, whose Claude AI model identifies the tiles. Only the list of tiles comes back to you.
• We do not store your photo. Our server keeps no copy once your tiles are returned.
• Your IP address is used to limit how many photos can be read per minute, to prevent abuse.

Under Anthropic's terms for its commercial API, Anthropic does not use your photo to train its models, and deletes it within 30 days, unless it must keep it longer to comply with the law or to investigate misuse. See Anthropic's data retention and privacy policy for details.

Everything in the picture is sent, not just the tiles, so please photograph only your rack, not people's faces or other players' tiles.

1.4. Analytics

We use Plausible to count visits to our pages. Plausible uses no cookies and collects no personal data. It records things like the page visited, the site that referred you, your browser and device type, and your approximate location. It does not store your IP address: it uses it only to tell visitors apart for a single day, and the means of doing that is deleted every 24 hours. Plausible stores its data in the EU.

1.5. Hosting and Request Logs

Our site is hosted by Cloudflare. Like any web host, Cloudflare receives your IP address and browser details when your browser loads a page. When one of our tools sends a request to our server, Cloudflare records it in a log we use to find and fix problems: the address requested, the time, your IP address, your browser and your approximate location. The log does not include what you sent, such as your tiles or a photo, and it is deleted automatically within 7 days.

Our pages also use fonts from Google Fonts. Your browser downloads them from Google, which receives your IP address and browser details when it does.

2. How We Use Your Information

We use this information to:

• Provide and operate the Service, such as analyzing hands and reading photos
• Respond to messages you send us
• Prevent abuse and keep the site secure
• Understand, in aggregate, which pages and features people use, so we can improve them

We never sell your personal information.

3. Data Sharing

We share limited information only with:

• Cloudflare, which hosts the site (see 1.5)
• Anthropic, only when you use the Photo button, to read the tiles in your photo (see 1.3)
• Plausible, for privacy-friendly visit counts (see 1.4)
• Google Fonts, which serves the fonts our pages use (see 1.5)
• Legal authorities if required by law or to protect our rights

We do not sell or rent your information to third parties.

4. Data Retention

We do not keep accounts or a database of our users. What we do hold, we keep only as long as needed:

• Request logs are deleted automatically within 7 days.
• Photos of your tiles are not retained at all (see 1.3).
• Emails you send us are kept as long as needed to respond and follow up.
• Information saved on your device stays there until you clear it.

You may ask us to delete your emails to us at any time by contacting us at info@mahjonghandhelper.com. Some data may be retained if required by law.

5. Cookies & Local Storage

We do not set cookies. We use your browser's local storage to remember your hand, settings and progress on your device (see 1.2). Plausible does not use cookies or local storage either.

You can clear local storage in your browser settings at any time. The site keeps working; it simply starts fresh.

6. Your Rights

Depending on your location and applicable law, you may have the right to:

• Access the personal data we hold about you
• Request corrections to inaccurate data
• Request deletion of your data
• Receive a copy of your data in a portable format

Because there are no accounts, the only personal data we are likely to hold about you is email you have sent us. To exercise these rights, contact us at info@mahjonghandhelper.com.

7. Children's Privacy

The Service is not intended for children under 13. We do not knowingly collect personal information from children under 13. If you believe we have collected such information, please contact us so we can delete it.

8. Data Security

We use reasonable technical and administrative measures to protect your data, but no online service can be 100% secure. You use the Service at your own risk.

9. Changes to This Policy

We may update this Privacy Policy as the Service evolves. Changes become effective when posted on the website. Continued use of the Service means you accept the revised Privacy Policy.

10. Contact

If you have privacy questions, contact us at info@mahjonghandhelper.com.