CardMatcher for Cardmarket

Privacy Policy

Last updated September 1, 2026

In short: CardMatcher does not collect, transmit, sell, or share any of your data. Everything it stores stays on your own device, inside your browser.

What CardMatcher does

CardMatcher is a browser extension for cardmarket.com. On a card's offer page, it reads the seller list that is already visible in your browser (seller name, price, and available quantity) and lets you save it locally so you can compare several cards at once and find a seller who can supply everything in one order.

CardMatcher is an independent, unofficial tool. It is not affiliated with, endorsed by, or produced by Cardmarket / Cardmarket GmbH.

What data is stored, and where

The cards you save (seller names, prices, quantities, and the quantities you need), plus your theme and language preference, are stored using your browser's local extension storage (chrome.storage.local). This data:

never leaves your device — CardMatcher has no server, and makes no network requests of its own;
is not visible to the developer, to Cardmarket, or to any third party;
is not used for advertising, analytics, or tracking of any kind — CardMatcher includes no analytics or tracking code;
stays until you remove a card, use "Reset", or uninstall the extension.

Permissions CardMatcher requests, and why

Access to cardmarket.com pages: required so the extension can read the offer table on the page you're already viewing and show its panel there. CardMatcher does not run on, or read, any other website.
Local storage: required to remember the cards you save between browsing sessions.

Accounts and sign-in

CardMatcher does not require an account, sign-in, or any personal information to function.

The "Support this project" link

The optional heart-shaped link in the extension opens a PayPal.me page in a new tab, entirely at your choice. That page is operated by PayPal, not by CardMatcher, and any payment you choose to make there is handled under PayPal's own privacy policy. CardMatcher never sees or stores anything related to this.

Changes to this policy

If this policy changes, the "last updated" date above will be revised accordingly.