Privacy Policy

Last updated September 29, 2026

This policy explains what Rung Chess ("Rung", "we", "us"), at rungchess.com, collects, why, and what you can do about it.

If you play without an account

• Progress on your device. Your climb, daily streak and settings are saved in your browser's local storage. This stays on your device and isn't sent to us.
• Anonymous answer data. When you answer a puzzle, we record which puzzle it was, the move you played, whether it was right, how many hints you used, how long you took, and the app version. This is tied to a random ID created in your browser, not to your name or email. We use it to find puzzles that are too easy, too hard, or broken.
• Reports. If you use "Report a problem", we receive the reason you picked, any note you write, and the puzzle and move. Please don't put personal information in the note.

If you sign in with Google

Signing in is optional. It unlocks levels past 3 and syncs your progress across devices. When you choose "Continue with Google", Google shares the following with us, and nothing else:

• Your email address
• Your name and profile picture link, as set on your Google account
• A Google account identifier

We use this only to create your account, sign you in, and keep your progress attached to it. We store your progress (levels cleared, scores, streaks, which puzzles you've seen, and settings) with your account. We never see or store your Google password, and we don't access your Gmail, contacts, Drive or any other Google data.

Google user data. Rung's use and transfer of information received from Google APIs follows the Google API Services User Data Policy, including the Limited Use requirements. We don't use Google user data for advertising, we don't sell it, and we don't share it with anyone except the service providers below, who process it only to run Rung.

Your anonymous answer data stays anonymous after you sign in. It isn't linked to your account.

What we don't collect

• No passwords. Rung has no passwords at all.
• No payment details, location, contacts or microphone and camera access.
• No advertising or cross-site tracking, and no analytics services.

Service providers

We use a few companies to run Rung. They only handle data as needed to provide their service:

• Supabase stores accounts, synced progress, anonymous answers and reports, and handles sign-in.
• Vercel hosts the website. Like any web host, it processes technical data such as your IP address to deliver pages and protect against abuse.
• Google provides "Sign in with Google" and serves the fonts the site uses. When fonts load, Google receives your IP address and browser information.

Puzzles come from the public Lichess puzzle database. Links to Lichess games open lichess.org, which has its own privacy policy.

Cookies and local storage

Rung doesn't set advertising or tracking cookies. It uses your browser's local storage to remember your progress, settings (theme and sound), a random anonymous ID, and, if you're signed in, your sign-in session.

How long we keep data

• Your account and synced progress are kept until you delete your account.
• Anonymous answers and reports are kept to improve the puzzles. Because they aren't tied to your name or email, we can't find yours to remove them individually.

Deleting your account and your choices

• Delete your account any time: open the account menu (top right), then "Delete my account". This immediately and permanently deletes your account and synced progress.
• Stop sharing with Google by removing Rung at myaccount.google.com/connections.
• Clear local progress with "Reset progress" at the bottom of the home page, or by clearing your browser's site data.
• Ask us for a copy of your data, a correction, or deletion by emailing rungchess@gmail.com. Depending on where you live (for example the EU, UK or California), you may have additional rights, and we'll honor them.

Security

All traffic is encrypted with HTTPS. Sign-in is handled by Google, so there's no password for us to lose. The database only lets a signed-in player read or change their own progress. No system is perfectly secure, but we collect as little as possible so there's little to expose.

Children

Rung isn't directed at children under 13, and we don't knowingly collect personal information from them. Signing in requires a Google account. If you believe a child under 13 has given us personal information, email rungchess@gmail.com and we'll delete it.

Changes to this policy

If we change this policy, we'll update the date at the top. If a change affects how we use personal information in a significant way, we'll say so in the app.

Contact

Questions about privacy: rungchess@gmail.com.