The free method, step by step
- 01Look at the URL first. Many platforms host on their own domain or a subdomain of it, so the answer is often in the address bar before you do anything.
- 02Click through to the checkout. Even when the sales page sits on a custom domain, payment usually hands off to the platform and names it.
- 03View the page source and search for the platform name. Asset URLs, CSS class prefixes and script hosts almost always leak it.
- 04Look at the script hosts specifically. A page can be styled to look like anything, but it still loads its JavaScript from somewhere.
- 05Check the login link. « Members area », « My courses » or « Sign in » usually points straight at the platform.
- 06Look at the footer. Several platforms require attribution on lower plans, which is a free answer.
- 07If nothing matches, look for a site builder rather than a course platform · a custom stack usually means WordPress, Webflow or Framer plus a separate checkout.
A custom domain proves nothing. Almost every platform supports them, which is exactly why the source and the checkout are the reliable tells.
