Frequently Asked Questions

Cardmarket Companion is a free, unofficial browser addon (also called a plugin, extension or enhancer) for Cardmarket — Europe's largest trading card game marketplace. It automatically fills in listing prices using real-time trend data, shows card images in search results, and tracks your listing session live. It works for all TCG games available on Cardmarket: Magic: The Gathering, Pokémon, Yu-Gi-Oh, and more.

Both! Cardmarket Companion is available as a Chrome extension on the Chrome Web Store, and as a Firefox addon on the Mozilla Add-ons site. Both desktop versions are actively maintained and receive the same features. There is currently no mobile version.

These terms all refer to the same type of software: a small program you install in your browser that adds new functionality to a website. 'Extension' and 'addon' are the most common terms (Chrome uses 'extension', Firefox uses 'addon'), while 'plugin' and 'enhancer' are informal synonyms. Cardmarket Companion is all of these — an addon, extension, plugin and enhancer rolled into one.

For Chrome: visit the Chrome Web Store and click 'Add to Chrome'. For Firefox: visit Mozilla Add-ons (addons.mozilla.org) and click 'Add to Firefox'. Once installed, navigate to any Cardmarket listing page and the addon activates automatically — no sign-in or account needed.

No, Cardmarket Companion is completely free. There is an optional donation button to support the developer, but all features are available without payment. There is no premium tier or subscription.

Yes, it is safe. Cardmarket Companion does not collect, store, sell or transfer any of your personal or pricing data. The Chrome Web Store and Firefox Add-ons listing both confirm this. The extension only reads Cardmarket pages you actively visit to inject its enhancements — it never accesses unrelated sites.

No. Cardmarket Companion is an unofficial, independent browser addon built by a Cardmarket seller for the community. It is not affiliated with, endorsed by, or connected to Cardmarket (MagicCardMarket SAS). Use of the Cardmarket name is for descriptive purposes only.

Pro Mode is a smart competitive pricing feature that automatically sets your listing price just below the first professional or power seller on Cardmarket. You can choose to undercut by a fixed euro amount or by a percentage, and configure the thresholds to match your strategy. It's the most advanced feature of the Cardmarket Companion plugin.

Yes. The Selectable Pricing Mode feature lets you pick whether the addon prefills your listing with the first available price or the average price of similar listings. You can also select the trend period: 1 day, 7 days, or 30 days. This gives you fine-grained control over your Cardmarket pricing strategy.

Cardmarket Companion works for all trading card games available on Cardmarket, including Magic: The Gathering (MTG), Pokémon TCG, Yu-Gi-Oh!, Flesh and Blood, Lorcana, One Piece, Dragon Ball Super Card Game, and more. Any card that can be listed on Cardmarket benefits from the addon's price prefilling and search enhancements.

Yes. Cardmarket is used across Europe — in Germany, France, Spain, Italy, the Netherlands, Poland, and many more countries. Cardmarket Companion works on all regional versions of Cardmarket since it operates directly in your browser on the cardmarket.com domain.

Cardmarket Companion focuses specifically on seller productivity: automatic price prefilling, pro competitive pricing, live listing tracking, and copy/share features. It is actively updated, free, and privacy-first. While other extensions may focus on buyer features or different aspects of the Cardmarket experience, Cardmarket Companion is purpose-built for sellers who list cards frequently.

Yes. The addon includes built-in update notifications. Whenever a new version is released, a brief message describes the improvements or new features added — so you always know what's changed in your Cardmarket extension.

Use the built-in Feedback & Contact feature available directly in the extension popup. You can also leave a review on the Chrome Web Store or Firefox Add-ons page. All feedback is read and actively used to improve the addon.