Zenblock Privacy Policy

Last updated: June 18, 2026

Zenblock ("the extension," "we," "our") is a Firefox browser extension that helps you block distracting websites. This policy explains what information the extension handles and how that information is used.

Summary: Zenblock does not collect, sell, or transmit your personal data to us or to any analytics service we operate. Your settings and activity counters stay on your device.



Who we are

Zenblock is published as a Firefox add-on (Add-on ID: zenblock@hari.dev). For privacy questions, contact the developer through the support link on the Firefox Add-ons listing for Zenblock.



Information we do not collect

Zenblock does not:

• Require an account or sign-in
• Run analytics, crash reporting, or advertising trackers
• Send your browsing history, block lists, or settings to our servers (we do not operate backend servers for this extension)
• Read or store the content of web pages you visit (text, passwords, form fields, etc.)
• Sell or share your data with third parties for marketing

This matches the extension’s Firefox manifest declaration: no data collection.



Information processed on your device

To provide blocking, scheduling, time limits, and zen mode, Zenblock stores and processes the following locally in your browser using Firefox’s storage API (browser.storage.local). This data never leaves your device unless you export it yourself (e.g. via browser backup tools) or uninstall the extension.

| Data | Purpose |
|------|---------|
| Block list entries (domains, patterns) | Sites you chose to block |
| Categories and enabled category lists | Group blocking you configured |
| Schedules | When blocking should be active |
| Daily time limits and usage counters | Per-site time budgets and time spent today |
| Settings (on/off, theme, block message, redirect URL, private-window blocking) | Your preferences |
| Block statistics (e.g. blocked-attempt counts by day) | Shown in the popup; not sent anywhere |
| Zen mode session state and zen-specific block lists | Time-boxed lockdown feature |
| Active tab URL (temporarily, in memory) | Used for “block this site” and to decide whether a navigation should be blocked |

URL handling: When you load a page, the extension inspects the URL of the navigation (hostname and path) and compares it to your rules. That comparison happens entirely on your device. Matching visits may be redirected to the extension’s built-in block page or, if you configured one, a custom redirect URL you entered.

Typing challenge (zen mode): Text you type to unlock zen settings is compared locally to a stored passage. It is not uploaded or logged by us.



Permissions and why they are used

| Permission | Why |
|------------|-----|
| storage | Save your settings and lists locally |
| webRequest / webRequestBlocking | Block or redirect navigations to sites on your list |
| <all_urls> | Evaluate any site URL against your block rules |
| tabs | Read the active tab for quick-add and re-check open tabs when schedules or limits change |
| alarms | Schedule checks and zen session timers |
| idle | Pause time-limit counting when you are away from the keyboard |
| notifications | Optional local notifications (e.g. zen session ended, private window blocked) |



Third-party services

Google Fonts

The extension’s popup, settings, and block pages load typography from Google Fonts (fonts.googleapis.com / fonts.gstatic.com) when those pages are opened. Your browser may connect to Google’s servers to download font files. We do not send your block lists or browsing data to Google as part of this extension’s code; however, Google may receive standard web request data (such as IP address) according to Google’s privacy policy. If you prefer not to load these fonts, you may use browser-level tracking protection; the extension will still function with fallback system fonts.

Websites you visit

When a site is blocked, you may be shown the extension’s block page or sent to a redirect URL you configured. Those destinations are outside Zenblock and governed by their own policies.

Mozilla / Firefox Add-ons

If you install or update Zenblock from Firefox Add-ons, Mozilla processes that download according to Mozilla’s privacy policy.



Data retention and deletion

All extension data remains on your device until you:

• Change or clear it in Zenblock’s settings, or
• Remove the extension from Firefox, or
• Clear extension data via Firefox’s add-on/storage settings

Uninstalling the extension removes its stored data from your browser profile (subject to Firefox’s own behavior for extension storage).



Children’s privacy

Zenblock is not directed at children under 13, and we do not knowingly collect personal information from anyone.



Changes to this policy

We may update this policy when the extension changes. The “Last updated” date at the top will be revised. Continued use after an update means you accept the revised policy. Material changes may also be noted in release notes on the add-on listing.



Your rights

Because we do not operate a cloud account or store your data on our servers, requests to access or delete “your data with us” generally do not apply—your data is already under your control in Firefox. You can review, change, or delete it using the extension settings or by removing the add-on.

If you are in a region with specific privacy rights (e.g. GDPR, CCPA), you may contact us through the add-on listing support channel with questions about this policy.



License

Zenblock is open-source software distributed under the MIT License. Source code is available with the published add-on package for review.