Questions people send in

If yours is not here, the Discord is the quickest way to reach me.

What does it actually do?
It adds things to the Cardmarket pages you already use. On a card page it fills the listing price for you from trend data and can undercut the professional sellers by a margin you set. On search and want lists it shows real card art instead of a camera icon. On an order page it turns each line into something you tick off while you pull cards, and flags quantities, odd conditions and odd languages. Everything else on the site works exactly as before.
Which browsers does it work in?
Chrome, Edge and any other Chromium browser through the Chrome Web Store, and Firefox through Mozilla Add-ons. Both are the same extension and get the same updates. Desktop only. There is no mobile version, because Cardmarket selling on a phone is a special kind of pain nobody asked me to solve yet.
Is it free? Is there a paid version?
Free, with no paid tier, no trial and no locked features. There is a Buy me a coffee link for anyone who wants to chip in, and that is the whole business model.
Does it collect my data?
No. Your prices, listings and orders never leave your browser. The extension reads the Cardmarket page you are on and writes into the same page. Your settings are stored locally in the browser. The Chrome Web Store and Mozilla listings both carry that declaration, and you can check the requested permissions on either store page before installing.
Do I need an account or my Cardmarket password?
Neither. It works on the pages of whatever session you are already logged into, and it never asks for credentials. If anything ever asks you for your Cardmarket password in the name of this extension, it is not this extension.
How do I install it?
Open the Chrome Web Store or Mozilla Add-ons listing and click add. Then open any Cardmarket card page and the price box will already be filled in. Settings live on the extension's options page if you want to change the pricing mode or the per-page toggles.
What is the difference between the pricing modes?
Trend follows Cardmarket's own trend value over 1, 7 or 30 days. Lowest price takes the cheapest listing matching your filters, average price takes the average of them. Pro mode ignores all three and instead looks for the first professional or power seller in the list, then places you just under them by a fixed amount or a percentage. On top of whichever mode you pick, you can apply an offset and a minimum floor price.
Will it underprice my cards?
That is what the floor price is for: when the calculated price lands below the minimum you set, the minimum is used instead. It is worth setting before your first bulk session. A card with a two-cent trend is not worth listing at two cents.
What does it do on order pages?
Clicking a line marks that card as picked; it strikes through and the counter in the bar shows how many lines and cards remain. The state is saved per order, so if you stop halfway the order remembers. Lines with two to four copies are tinted amber and five or more red, there is a switch in the bar above the list to regroup the order by expansion, and cards below Near Mint or in a language different from the rest of the order are flagged.
Which games and which country sites are supported?
All of them. The extension works on the structure of Cardmarket pages rather than a per-game database, so Magic: The Gathering, Pokémon, Yu-Gi-Oh!, One Piece, Lorcana, Flesh and Blood and the rest behave identically, on whichever regional version of the site you use.
Is this made by Cardmarket?
No. It is an unofficial extension written by one seller, with no connection to Cardmarket (Sammelkartenmarkt GmbH & Co. KG). The Cardmarket name appears here only to describe what the extension works with.
Something is broken, or I want a feature. Where do I go?
The Discord is the fastest route, and there is a feedback button inside the extension that reaches me directly. Most of what shipped in the last few versions started as a message from someone using it.

Nothing left to check?

It takes about thirty seconds, and the feature list is there if you want the long version first.

Add to Chrome, freeAdd to Firefox

Works on Edge too. No account, no sign-in.