Training progress
Attempts, ratings, reviews, streaks, bookmarks, and achievements power your learning history.
Account data · kept while activePrivacy controls
Your data, your move
Chess training works with essential storage alone. Optional analytics stays off unless you choose it on this device.
Current setting
Essential only by default
This device
Choose what is active
Essential data
Required for secure sign-in, CSRF protection, saved training progress, and your board and theme preferences.
- No advertising profiles
- No sale of personal data
- Cannot be disabled while using the service
Optional analytics
Helps us understand visits, page speed, and whether recommendations and shared puzzles lead to useful training. It never changes puzzle access, ratings, or account features.
- Google Analytics page-usage measurement
- Sampled, first-party performance totals and percentile histograms without URLs or identifiers
- Daily recommendation impression, click, and outcome totals without user, session, route, or puzzle identifiers
- Screened daily search-topic and search-to-puzzle-start totals without stored user, session, IP, referrer, or user-agent identifiers
- Allow-listed API status and latency histograms without URLs, payloads, or visitor identifiers
- Daily puzzle-share, shared-link arrival, attempt-start, completion, and solve totals by sharing method—without stored puzzle, account, session, IP, referrer, or user-agent identifiers
- Can be changed here at any time
Data map
What each kind of data does
Device preferences
Theme, board options, recent puzzles, guest progress, and completed attempts waiting to sync stay in browser storage on this device.
Local only · removable in your browserSecurity records
Recent device, IP, and account events help you recognize access and help us investigate misuse.
Restricted · purpose-limitedProduct and performance totals
When allowed, loading-metric histograms, recommendation outcomes, screened search topics, search-to-puzzle-start conversions, share-funnel outcomes, and API status/latency histograms are stored as daily aggregates. Search topics are visible in reports only after five searches in the selected period.
Optional · no account or session IDFull policy
Details without the legal maze
What we collect and why
We collect the account information you provide, your chess-training activity, preferences needed to operate the interface, security records, and messages sent through the contact form. If you use Google sign-in, we keep the verified email, display name, and Google's stable account identifier; we do not retain Google access or refresh tokens.
We use it to run and secure your account, send verification, recovery, and one-time onboarding messages, personalize puzzle difficulty, maintain ratings and reviews, prevent manipulation, respond to support requests, and improve reliability when optional analytics is allowed. We do not enroll accounts in recurring marketing email without a separate choice.
Cookies, browser storage, and third parties
Essential cookies keep sessions secure and remember this privacy choice. Browser storage remembers visual settings and guest training progress. Clearing site data removes device-local preferences and may sign you out.
When you allow optional analytics and Google Analytics is configured, Google receives usage measurement and may set analytics cookies. When Gmail delivery is configured, Google also processes the recipient address and contents of verification, password-reset, and contact messages.
Advertising is currently disabled. We do not sell personal information.
Retention and protection
Account and training history is retained while your account is active because it powers the service. Read notifications are normally removed after 90 days, expired unread notifications after 180 days, and terminal push-delivery records after 30 days. Push subscription capability data is encrypted and removed when the installation is revoked or the account is deleted.
Expired session metadata is removed, product and performance observations are aggregated, and optional search-topic, share-conversion, and API-reliability aggregates are retained for up to 400 days. Limited security records may be retained to investigate abuse or satisfy legal obligations.
Passwords are hashed with Argon2id and never stored in readable form. Access is restricted to operational needs, and production traffic must use encrypted HTTPS connections.
Your rights and choices
You can update account information, change this device's analytics preference, disable push categories, remove installed devices, request a copy of your data, or request account deletion. Browser or operating-system notification permission is separate from your choices on this site and can also be changed in device settings.
Chess Puzzle Vault is intended for a general audience and is not directed to children under 13. If you believe a child submitted personal information, contact us so we can remove it.