Grade coins while you browse

The Million Coins Project extension for Chrome puts an estimated grade range on coin photos as you scroll through eBay and Heritage Auctions listings, and grades both sides of a listing you open with the same model and error bars as the web app.

On search results

Each coin image gets a small badge with a grade range as it scrolls into view. These are quick screens: one side of the coin, one pass of the model, shown as a 90% range because one side is less certain than two. Free accounts get 30 a day; Pro gets 1,000.

On a listing

The badge becomes a button: Grade both sides · 1 credit. Clicking it grades the first two gallery photos as obverse and reverse with the full protocol. If anyone has graded that listing before, it costs nothing. Pro users can make this automatic.

Auto or manual

The popup has a master ON/OFF switch, per-site switches, and a choice between grading tiles automatically or showing a grade button when you hover over an image.

Privacy

Your browser fetches the listing photos from the listing site, exactly as it does to display them, and sends them to our grader. We never fetch from eBay or Heritage ourselves. Quick screens are not stored; grades you click for appear in your history.

Install (beta)

The extension is in beta ahead of its Chrome Web Store listing. Until then it installs as an unpacked extension, which takes a minute:

  1. Download the extension and unzip it somewhere you'll leave it (Chrome loads it from that folder).
  2. Open chrome://extensions, turn on Developer mode (top right).
  3. Click Load unpacked and choose the unzipped folder. Pin the coin icon from the toolbar puzzle menu if you like.

Works in Chrome and other Chromium browsers (Edge, Brave, Arc). Firefox and Safari builds will follow the store listing.

Connect your account

The extension uses the same sign-in as this website. There is no separate account and nothing to paste.

  1. Sign in to Million Coins Project in the same browser profile you installed the extension in.
  2. Click the extension icon. The popup shows your email, your plan, and your credits. That's it: it's connected.
  3. If the popup says sign in instead, sign in here first and reopen the popup. You can also sign in from the popup directly.

Badges on listing sites read sign in to grade until the account is connected. Signing out of the website disconnects the extension too.

Good to know

  • A badge that says can't grade means the photo failed our quality check: no clear coin, too small, blurry, or heavy glare.
  • Slabbed coins photographed through plastic often trip the glare check. The grade on the label is a better source anyway.
  • One-side screens agree with the two-side grade within a point about seven times in eight. Treat them as a filter, not a verdict.
  • Every result shows the model version that produced it. Something look wrong? Tell us.