Privacy Policy
Last updated: 17 August 2026
Hong Kong Lot Viewer ("the tool", "we") is an independently operated tool, offered on free, trial, and paid tiers. This policy explains what information is collected when you create an account, why, and how you can control it.
Information we collect
- Account information — a password, plus either your email address or a username of your choosing. If you choose a username, we do not collect or store a real, deliverable email address for that account. Passwords are handled by Firebase Authentication (our identity provider); we do not see or store your password in plain text.
- Tier and trial data — your account's tier and its trial window's start and expiry dates, stored in our database (Cloud Firestore) so the app knows what features to unlock.
- Business Pro payment information — for paid Business Pro subscriptions arranged via the Portal, card payment is processed by Stripe, a third-party payment processor; we never see or store your complete card details. Stripe collects and processes what it needs to take payment (e.g. card network, last 4 digits, billing name/email) under its own privacy policy. Where payment is instead made by bank transfer, no card data is collected by anyone — your bank handles that transfer directly.
- We do not use cookies or local storage for advertising or cross-site tracking, and we don't track or limit which or how many devices an account is used on. Local storage is used only for your sign-in session, your language preference, and a short list of your own recent search terms (kept only in your browser, for your own convenience — never sent to us or anyone else).
- We do not use Google Analytics or any other analytics/tracking SDK. The only usage metric we keep is a single anonymous running total of page views (Cloud Firestore), with no per-user identity, session, device, or location data attached to it.
How we use this information
- To create, secure, and authenticate your account.
- To determine your tier and whether your 1-week trial window is still active.
- To send you account-related messages where necessary (e.g. a password-reset email, sent by Firebase on our behalf).
Where your information is stored
Account authentication is provided by Firebase Authentication, operated by Google, which may process authentication data in the United States. Your account and plan data is stored in our Cloud Firestore database, located in the Hong Kong (asia-east2) region. Some features — currently DD Lot number search, address/building name search, and RVD Statistics — are resolved by our own Cloud Functions rather than your browser querying the government service directly; these are currently deployed in the United States (us-central1) and, for signed-in users, receive your account's authentication token to confirm you're entitled to use the feature. They are not used to log, store, or otherwise retain what you search or view. Google acts as our infrastructure provider for both Firebase Authentication and Cloud Functions; see Google's Privacy Policy for how they handle data at the infrastructure level.
Government map data
The map itself displays open data from Hong Kong Government sources (including the Lands Department, Planning Department / Town Planning Board, Buildings Department, Rating and Valuation Department, Development Bureau, Transport Department, and Highways Department, obtained via the CSDI Portal, DATA.GOV.HK, and Esri China (Hong Kong) Ltd.). Some layers and actions — including the Zoning and Village Environ overlays, and loading lots around your current map view — query the relevant government or Esri service directly from your browser, without passing through our own systems at all. Others — currently DD Lot number search, address/building name search, and RVD Statistics — are resolved by our own Cloud Functions instead (see "Where your information is stored" above); in neither case do we collect, log, or store what you search or view, and we do not send your account, email, or other identity information to the external government or Esri services themselves. Access to these external services is outside our control and may be unavailable, degraded, or discontinued at any time without notice, which may cause a layer or search to stop working. This tool is an independent project and is not operated, endorsed, or affiliated with the Government of the Hong Kong Special Administrative Region or any of its departments; see our Terms of Use for more.
Data retention
We retain your account and plan data for as long as your account remains active, unless a shorter retention period applies to a particular type of data. If you close your account, we will delete your personal data within a reasonable period, subject to any data we are required or permitted to retain by law, or that is reasonably necessary for legitimate business, security, fraud-prevention, or dispute-resolution purposes.
Your rights
You can ask to access, correct, or delete your personal data at any time by emailing info@hklotviewer.com. We will handle requests in accordance with applicable data protection law.
Service providers
We use third-party service providers to operate the tool, including Google Firebase/Google Cloud for authentication, database, and application infrastructure, and Stripe for card payment processing (Business Pro subscriptions only). These providers may process personal data on our behalf to provide their services, and are subject to their own privacy policies and contractual obligations.
Security
We rely on Firebase's security infrastructure and Firestore security rules that restrict every account to reading and writing only its own data. No method of transmission or storage over the internet is 100% secure, and we can't guarantee absolute security.
Children's privacy
This tool is not directed at children under 13, and we do not knowingly collect personal data from them.
Changes to this policy
We may update this policy from time to time. Continued use of the tool after a change constitutes acceptance of the updated policy.
Contact
Questions about this policy can be sent to info@hklotviewer.com.