Last updated 8 November 2026.
In short: there are no accounts, no analytics and no ads. What you enter stays in your browser or on your phone. Coin Spotter sends the photos you scan, and what you typed about them, to the AI provider you chose, using your own key, and to nobody else.
This website
numismaticarchivist.com and its apps are hosted on Vercel. Like any web host, Vercel handles each request, including your IP address, to deliver the page.
If you choose light or dark instead of your system's setting, the choice is kept in a cookie named na-theme on numismaticarchivist.com, so every app opens in the same theme, and in your browser's local storage. It holds only light or dark. Choosing System again removes it. There are no other cookies.
Flip Studio
Your coin lists, label settings and separator cards are kept in your browser's local storage, on your computer. They aren't sent anywhere. A backup is a file you download yourself. Clearing the site's data in your browser deletes them.
Coin Spotter
Your API key
Coin Spotter runs on Gemini (Google) or Claude (Anthropic) with a key you create. In Chrome the key is kept in the extension's local storage (chrome.storage.local), which Chrome doesn't sync. On Android it's kept in the phone's encrypted keystore. It is sent only to its own provider.
What is sent, and to whom
- When you scan, the photos, the listing's title, price and description (in Chrome) or the asking price and note you typed (on Android) go to the provider you chose, and nowhere else. Check market price also lets the provider search the web for that coin.
- On supported marketplace sites, the Chrome extension reads the listing you have open so it can show it in the side panel. Nothing leaves your computer until you scan.
- Gemini keeps each interaction on Google's servers by default; Coin Spotter deletes it as soon as a scan ends. A Gemini key without billing runs on Google's free tier, where Google may use what you send to improve its products.
The providers' own terms apply to what they receive: Gemini API terms and Anthropic's commercial terms.
What is kept
- Chrome: the results of your last 60 scans, one per listing, in the extension's local storage, so reopening a listing doesn't cost a new scan.
- Android: your last 40 scans with their photos, in the app's private storage. Android's automatic backup is off for the app, so none of it goes to Google Drive. Deleting a scan deletes its photos, and uninstalling the app deletes everything.
Changes
If what the apps store or send changes, this page changes with it, and the date at the top says when.