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Privacy Policy — Price Comparator

Extension version: 2.0.0
Last updated: August 27, 2026
Developer: celsoandres.com

In short

  • Everything is stored only in your browser — the extension has no server or backend of any kind.
  • It only opens and reads the pages of the stores you added to your list, and only when you start a search.
  • The AI model that compares products runs inside your browser — no text you type ever leaves your device.
  • There are no accounts, no tracking, no analytics, and nothing is sold or shared with third parties.
  • You can delete your data at any time by uninstalling the extension.

1. What the extension does

Price Comparator lets you type a product name once and see its price across up to five supermarkets that you configure — never stores chosen by us. When you search, the extension briefly opens a tab (or a minimized window, depending on your preference) for each store, reads that store’s search result the same way a person browsing normally would, and shows you the product and price it found.

There is no “cloud” version of this product: all the processing — from opening the tab to deciding which product is the right one — happens inside your browser.

2. What information it processes

Specifically, the extension handles this data:

  • Your settings: the name you optionally give your profile, your chosen language and country, the list of stores you added (name and search URL), and your operating preferences (how often the cache expires, whether tabs open in the background or in a minimized window).
  • What you type in the search box: used only to build the search URL for each store you configured — for example, turning “milk” into that store’s actual search URL. It’s never sent to any server of ours, because none exists.
  • The public content of each store’s results page you visit through the extension: product name, price, image, and availability — the same information you’d see if you opened that page yourself. The extension reads nothing from that page beyond that product listing.
  • A short history of your recent searches (up to 50) and a cache of recent results, so you don’t have to repeat the same search twice in a row.
  • A log of technical failures (up to 20) when the extension fails to parse a store’s page — this is diagnostic data that stays on your device, it isn’t sent to us.

3. Where that information lives

Everything above is stored exclusively using your browser’s chrome.storage.local API — the same mechanism any extension uses to remember your preferences. None of this is replicated on a server: we don’t have one, we don’t need one, and the extension’s code makes no network calls except opening the store pages you chose yourself.

No backend means exactly that. If you delete the extension, you delete the data. There’s no copy anywhere else that we could keep, lose, or hand over to a third party, because it never leaves your browser.

4. The AI model that runs on your device

To decide which of the products a store shows matches what you searched for, the extension uses a text-comparison model that can include a semantic embeddings model (based on transformers.js) bundled inside the extension itself. This model runs entirely in your browser via WebAssembly: it doesn’t connect to any external AI service, it doesn’t send your searches or product titles anywhere, and it keeps working offline once the extension is installed.

5. Permissions it requests, and why

Permission What it’s used for
storage Store your settings, results cache, and history locally.
tabs Open and close each store’s tab during a search, and know when it finished loading.
scripting Read the product listing from the already-loaded results page — nothing else.
sidePanel Show the extension’s interface in Chrome’s side panel.
Access to a specific site (optional host permission) Requested one at a time, only for the domains of the stores you add to your list — never broadly. You can revoke it at any time by removing that store from Settings.

6. What this extension does not do

  • It doesn’t create accounts or require you to log in anywhere.
  • It doesn’t sell, rent, or share your information with anyone — there’s no one to share it with, because it never leaves your browser.
  • It includes no analytics, behavioral tracking, or advertising of any kind.
  • It doesn’t access passwords, payment data, or the content of sites other than the ones you configured.
  • It doesn’t browse or act in the background — it only opens tabs when you explicitly press “Search.”

7. Your control over your data

From the Settings screen you can remove any store at any time — doing so also revokes the extension’s access permission for that site. To delete absolutely everything the extension has stored (settings, cache, history), simply uninstall it from chrome://extensions: since no copy exists outside your browser, none of your data remains anywhere else.

8. Changes to this policy

If the extension’s behavior changes in a way that affects what’s described here — for example, if some form of sync were added in the future — this page will be updated before that version is published, and the “Last updated” date at the top will reflect it.

9. Contact

For questions about this policy or how the extension works, you can reach out through celsoandres.com.