Last updated: July 22, 2026
SetCheck is a browser extension that helps Lego buyers and sellers on Vinted
quickly check a set's official retail price, piece count, and market value
while browsing. This page explains exactly what data SetCheck accesses,
stores, and sends — and what it doesn't.
What SetCheck does
When you view a Lego listing on Vinted, SetCheck reads the listing's title,
description, price, brand, and condition fields directly in your browser to
detect a Lego set number. If found, it looks up that set number using the
Brickset API and displays the results (RRP, piece
count, retirement status, etc.) as an overlay on the page.
What data SetCheck accesses
- Vinted page content (title, description, listed price, condition,
brand) — read locally in your browser, on Vinted pages only. This data
never leaves your browser except as described below.
- Your Brickset API key — which you provide yourself — stored locally
so SetCheck can make lookups on your behalf.
What data SetCheck sends, and to whom
- To Brickset's API: only the Lego set number(s) detected on the page,
plus your API key (required by Brickset to authenticate the request).
No other page content, no personal information, and no Vinted account
data is sent.
- Nowhere else. SetCheck does not use analytics, tracking pixels,
advertising SDKs, or any third-party services beyond Brickset's API.
What data SetCheck stores, and where
- Your Brickset API key — stored locally in your browser's extension
storage (
chrome.storage.local). It is never transmitted to us or to
any server we control.
- Cached lookup results — set data (RRP, piece count, etc.) is cached
locally for up to 7 days to avoid repeat API calls. This cache never
leaves your browser.
All of the above is stored only on your own device. SetCheck has no
backend server, no user accounts, and no database of its own — we (the
developers) do not receive, see, or have access to any of this data.
What SetCheck does not do
- It does not collect or transmit your Vinted account information,
browsing history, purchases, or messages.
- It does not sell, rent, or share any data with third parties.
- It does not use cookies, fingerprinting, or cross-site tracking.
- It does not automate purchases, listings, or messages on your behalf.
Permissions explained