Question 1

Where do I put the generated code?

Accepted Answer

Copy the <script type="application/ld+json"> snippet and paste it inside your page's <head> (or anywhere in the body), or use your CMS's structured data field. One script per page is fine, even with several types combined in @graph.

Question 2

How do I know if it's valid?

Accepted Answer

The tool parses the JSON and checks the required and recommended properties for every schema.org type it generated, flagging placeholders and relative URLs. Confirm eligibility for rich results with Google's Rich Results Test before publishing.

Question 3

Does it invent details?

Accepted Answer

No. It uses facts from the page you give it or from your description. Anything it can't know — a phone number, a date, a price — is inserted as a clearly marked placeholder and listed for you to replace.