Structured data can look correct in a template and still disappear from the HTML that a server returns. It can also be valid JSON while missing a field that a specific Google search feature requires. IndieSchema starts with that practical gap.
Paste one public page URL. IndieSchema fetches its initial HTML, extracts each JSON-LD block, lists the entity types, and checks common Google feature rules. A required gap is shown as a field name, not hidden inside a score. The exact Search Central page that supplied the rule sits beside the finding.
The boundary matters. Google supports several structured data formats and can process markup added with JavaScript. IndieSchema currently evaluates JSON-LD in the initial response only. It does not render JavaScript, decide whether the structured data truthfully matches visible content, or promise that Google will show a rich result. Even correct markup does not create that guarantee. Google’s Rich Results Test and URL Inspection remain the rendered checks to use before release.
The checker is free. It has no account, card, premium plan, ads, or upgrade nag. It does not save a response body or turn a private lookup into a directory listing. One URL goes in, one sourced preflight comes back, and the work stays yours.