Put a ring sizer, a diamond size chart or a gold calculator on your site
One line of code. Free for any jeweler, designer, blog or marketplace. No sign-up, no API key, and nothing about your visitors is tracked. Each widget is the same engine that runs CaratBase, sized to fit wherever you put it.
Two ways to run it
The free widget is genuinely free and always will be — the attribution line beneath it is what pays for the project. Pro is for the case where that line is the problem: a shop that does not want its visitors sent somewhere else, and would rather keep the inquiries its own tools generate.
No sign-up, no key, no expiry.
- All three widgets, unlimited pages
- Your brand color via
data-accent - Automatic height, mobile-friendly
- “Powered by CaratBase” line beneath each widget
- Widget links open CaratBase in a new tab
One domain. Cancel whenever; the widget drops back to free.
- Everything in free
- No attribution line
- Inquiries go to you — someone who uses your sizer and asks to be contacted is your lead, not ours
- Your call to action under the tool — “Book a fitting”, pointed anywhere on your site
- No links out — your visitors stay on your site
Pro is keyed to one domain. Paste the key into the widget and the attribution disappears; everything else keeps working exactly as before. If our license server is ever unreachable the widget quietly falls back to the free tier rather than breaking, so a paying customer sees an attribution line for a few minutes at worst.
Using a Pro key
Add data-key to the same div. Everything else stays as it is.
<div class="caratbase-widget" data-widget="ring-size"
data-key="cb_live_your_key_here"
data-cta="Book a fitting"
data-cta-url="https://yourshop.com/appointments"></div>
<script async src="https://caratbase.com/embed.js"></script>
data-cta and data-cta-url are optional — leave them out
and the widget simply has no button. Your key also works on localhost, so
you can build against it before the page is live.
Ring size finder
Converts between US, UK, European and Indian/Japanese sizes, and finds a size from a ring's inside diameter or a finger's circumference. The most requested tool on any jeweler's site.
Match your brand: add data-accent="#8A1C3B" to the div. Width: data-width="420px".
Diamond size chart
Any carat weight in any of ten shapes, drawn at true scale on a finger, with the face-up size in millimeters and a retail price range. Answers "how big is a 1.5 carat oval?" without a phone call.
The price shown is a G color, VS2 stone at retail; the link beneath goes to the full color-and-clarity grid on CaratBase.
Gold calculator
Weight in grams, pennyweight, tola or ounces, at any karat, priced at the live spot rate — plus the range a buyer will actually offer. Ideal for "we buy gold" pages and pawn or bullion sites.
Prices refresh every minute from the live market while the page is open.
Terms, in plain words
The widgets are free to use on any website, commercial or not. The one condition on the free tier is the small "Powered by CaratBase" line beneath each widget: leave it in place and unaltered. That line is how the project pays for itself, and removing it without a license is the only thing the license forbids. If you would rather not carry it, that is exactly what Pro is for. We may update a widget's design or data at any time; we will never inject advertising into it or collect your visitors' personal data through it. If you need a widget removed from a page, delete the two lines and it is gone.
Multiple widgets on one page work fine — add one div per widget and the
script once. Works on WordPress, Shopify, Squarespace, Wix, Webflow and plain HTML;
on platforms that strip scripts, use an "HTML" or "Embed" block.
Want a widget we don't have — a hallmark lookup, a gemstone valuer, a metal-weight estimator from ring size? Write to [email protected].