Find out what any website is built with.
Paste an address and see the platform behind it — the CMS, the WordPress theme and plugins, the Shopify theme, the JavaScript framework, the host and whatever is measuring it. Free, instant, and there is nothing to sign up for.
Public websites only. Private, internal and staging addresses are refused.
What the checker reads
Every platform leaves fingerprints in the page it serves — asset paths, generator tags, response headers, the names of the files it loads. The checker requests the page the way a browser would and reads them back.
- The platform
- WordPress, Drupal, Joomla, Ghost, Webflow, Wix, Squarespace and Framer, plus headless setups running on Contentful or Sanity.
- The store
- Shopify, WooCommerce, Magento and BigCommerce — and on Shopify, the theme it is running and whether that theme came from the theme store or was built for them.
- The WordPress theme and plugins
- The active theme slug, its published name, author and version where the stylesheet is readable, and every plugin directory the page loads assets from.
- The framework
- Next.js, Nuxt, Astro, SvelteKit, Remix, Gatsby, React, Vue, Angular — and the older furniture too, jQuery, Bootstrap and Elementor.
- Where it is hosted
- Cloudflare, Vercel, Netlify, CloudFront, Fastly, WP Engine, Kinsta, LiteSpeed, Nginx, Apache and GitHub Pages, read from the response itself.
- What is measuring it
- Google Analytics 4, Google Tag Manager, Meta Pixel, Hotjar, Clarity, Plausible and Fathom.
What it cannot tell you
It reads one page, once. It cannot see anything behind a login, anything decided on the server, or a plugin that loads nothing on the front end. A site behind a proxy that strips its headers will come back thinner than the truth, and a site that blocks automated requests will come back empty.
When it does not know, it says it does not know. There is no guessing pass, because a confident wrong answer is worse than a blank one for anyone using this to decide something.
Why we built it
Most people asking this question are about to inherit a site, rebuild one, or take over looking after one — and the answer changes what that costs. It is the first thing we look up ourselves before quoting a migration or a redesign, so it may as well be public.
If what comes back is a site you would rather somebody else looked after, that is a care plan, and the price is on the pricing page rather than behind a call.
Questions people ask
What CMS is this website using?
Paste the address into the box above and you will have the answer in a few seconds. We request the page the way a browser would, then read the response headers and the HTML for the fingerprints each platform leaves behind — asset paths, generator tags, cookie names, server headers. If it is WordPress you also get the theme and the plugin list; if it is Shopify you get the theme name.
How accurate is it?
Accurate when a site is built normally, and honest when it is not. A site behind an aggressive proxy, or one that rewrites its asset paths to hide them, will come back with less than the truth — and we say so rather than guessing. We would rather return nothing than return a confident wrong answer, because a wrong answer is worse than no answer for anyone using this to make a decision.
It found nothing. Does that mean the site is custom-built?
Sometimes, and that is a real and interesting answer. More often it means the site sits behind a proxy that strips the identifying headers, or it blocks automated requests, or the page is rendered entirely by scripts we do not run. A blank result is a limit of the method, not a verdict on the site.
Do you store the addresses people check?
The address you type appears in the result page URL, which means it is in our server logs like any other request, and those roll off on the normal retention schedule. We do not build a list from it, we do not attach it to you, and there is nothing to unsubscribe from because you have not given us anything to unsubscribe. The full position is in the privacy policy.
Can you check a site that is not public yet?
No. The checker only reaches addresses that resolve on the public internet — staging sites behind a password, anything on a private network and any internal address are all refused by design. If you want a private build looked at, book a call instead.
Why are you giving this away?
Because most of the people who need to know what a site is built on are about to inherit it, rebuild it or take over looking after it, and that is our work. If the answer sends you away happy, that is fine. If it makes you want somebody else to own the problem, our prices are published.
Check a site.
Yours, a competitor’s, or the one you are about to inherit. If you would rather talk it through, there is a 30-minute call.