Smartblock
Privacy Policy
Effective date: August 12, 2026 · Applies to the Smartblock Chrome extension and its companion backend API.
This policy is written to be read, not just filed. If anything here is unclear, the short version lives inside the extension itself under Settings → Privacy — this page is the longer, more precise version of the same promises.
Who this is
Smartblock is a Chrome extension that blocks sites you tell it to block and replaces them with a short lesson from a learning path you set up yourself. It is developed and operated as a single-developer product; "we" below refers to that operator.
What Smartblock never does
- Never reads your browsing history, open tabs, or bookmarks.
- Never sees the content of any page you haven't explicitly chosen to block.
- Never uses third-party trackers, advertising SDKs, or general-purpose analytics of any kind.
- Never requests access to a website until you personally add it to your block list.
- Never sells or rents your data, and never shares it for advertising, profiling, or analytics.
- Never lets a third party see a request from your browser. Smartblock pages talk to exactly one host: Smartblock's own backend. Everything else the product needs from the outside world — AI generation, lesson illustrations — is fetched by that backend on your behalf, so no outside service ever learns your IP address or which lesson you are reading.
- Never asks for your name, email address, or any account credentials. There is no sign-up.
What data we collect, and why
Everything below is collected only because the core product loop requires it, and nothing more:
| Data | Why we collect it | Where it's stored |
|---|---|---|
| A randomly generated device ID | To tell "the same installation" apart from another, without knowing who you are. Generated locally; not derived from or linked to your name, email, Google account, or any other identifier. | Your device (chrome.storage.sync) and our backend database, associated only with the ID itself. |
| The topics you type in (e.g. "Conversational French") | To generate your skill tree via an AI model. | Our backend database. |
The domains you choose to block (e.g. youtube.com) |
To know which sites you've chosen to intercept, and to build the redirect rule your browser uses. This is a short, explicit list you built — never your browsing history. | Your device and our backend database. |
| Your lesson, quiz, and simulation activity (answers, scores, transcripts) | To grade your work, personalize future lessons around what you've gotten wrong, and update your skill tree's progress. | Our backend database. |
We do not collect: your IP address for tracking purposes (it is visible to our server as it is to any web server, but is not logged, stored, or associated with your account beyond what's operationally necessary to serve the request), your general browsing history, the content of any page other than ones you've blocked, your device's other installed extensions or software, or any biometric or health information. We never receive or store your payment card details or your email address — if you buy a paid plan, those go directly to our payment processor, Stripe, and never touch Smartblock's servers or the extension (see "Payments" below).
How your data is used
- To generate and personalize your skill trees, lessons, quizzes, and simulations, via a third-party AI provider (currently OpenRouter). Only the specific content needed for that request is sent to the AI provider for that single call. We do not send your device ID, your full site list, or any data unrelated to the specific generation request.
- To illustrate lessons with freely-licensed photographs and diagrams from Wikimedia Commons. Our backend searches, downloads, and caches images; your browser loads them only from Smartblock's backend, never from Wikimedia.
- To keep your progress in sync across Chrome profiles via
chrome.storage.sync(Chrome's own sync — that data does not pass through Smartblock's backend). - To operate the service itself: generating your next lesson, grading your quiz, running your simulation, and computing progress statistics, returned only to you.
We do not use your data for advertising, do not build behavioral profiles beyond the learning product itself, and do not share it with data brokers or ad networks.
Payments
Smartblock is free to use. Optional paid plans (Plus and Unlimited) add more active courses and more monthly practice simulations. If you buy one:
- Your card details never reach us. Checkout is a hosted page operated by Stripe, our payment processor. You enter your card on Stripe's page, not ours; Smartblock's backend and the extension never see, handle, or store your card number, and never receive your name.
- Stripe collects your email to send a receipt. We do not receive or store your email address — it lives with Stripe, under Stripe's privacy policy.
- What our backend stores for a paid account: your Stripe customer and subscription identifiers, which plan you're on and when it renews, and a one-way hash of a "restore code" so you can move your plan to another device — all tied only to your anonymous random device ID, never your name or email.
- No card data, ever, in the extension. The extension contains no payment code and loads nothing from Stripe. Upgrading opens Stripe's hosted checkout in a normal browser tab; managing or cancelling opens Stripe's customer portal the same way.
- Entitlement is decided on our server from Stripe's signed notifications about your subscription — never from anything the extension reports.
How blocking works, technically
Smartblock uses Chrome's declarativeNetRequest API. Chrome itself evaluates whether a URL matches a blocked domain and performs the redirect; Smartblock's own code never sees the network request, its headers, or its body. Smartblock does not request the broader webRequest or tabs APIs.
Third parties
Four external services can be involved, and only four. Your browser talks only to our backend and — if and when you choose to buy a plan — to Stripe; the AI and image services are contacted by Smartblock's backend, never by you.
- Our own backend API — the only place your topics, blocked-site list, and lesson/quiz/simulation activity are sent, and the only host your browser loads anything from.
- OpenRouter (and the underlying model it routes to) — used solely to generate content server-side.
- Wikimedia Commons — used solely to find and download freely-licensed lesson illustrations.
- Stripe — our payment processor, and only if you choose to buy a paid plan. Your browser talks to Stripe directly at checkout so your card goes to Stripe and never through us; we receive back only your subscription's status and identifiers (never your card or email). If you never buy a plan, your browser never contacts Stripe. See "Payments" above and Stripe's privacy policy.
Citations generated for a lesson are verified against Wikipedia, OpenLibrary, and Crossref so fabricated sources can be removed. Those requests contain only a book title or case name — nothing about you.
No advertising network, analytics platform, or data broker is integrated into Smartblock at any layer.
Data retention and deletion
Your activity data is retained for as long as your Smartblock installation is active. You can delete a topic (and its skill tree) anytime from Settings → Skill tree. To remove everything, use Settings → Privacy → Delete all my data, which erases your account and all server-side records for your device ID; you can also export a copy of your data first from the same screen.
If you have a paid plan, you can cancel any time in one click from Settings → Plan → Manage subscription, which opens Stripe's customer portal; cancellation stops future charges and your account returns to the free tier at the end of the period you've paid for. Deleting your data also removes the subscription identifiers and hashed restore code we hold. Records Stripe keeps for its own legal and tax obligations (such as receipts) are governed by Stripe's privacy policy.
Children's privacy
Smartblock is not directed at children under 13 and does not knowingly collect data from them. If you believe a child has provided data to Smartblock, contact us and we will delete it.
Changes to this policy
If this policy changes in a way that affects what data is collected or how it's used, we'll update the effective date above and reflect the change in the extension's in-app privacy page before the change takes effect.
Contact
Questions about this policy or your data: open an issue on the project repository.