JSON-LD

JSON-LD is a way of embedding a hidden "label" inside a webpage that spells out exactly what the page's content is. Humans can read text and figure out, "ah, this is a product review" or "this is a company profile," but computer programs have a much harder time reading through prose and grasping its meaning. So if the page creator writes out ahead of time, in a fixed format, "this page is a product, its name is this, its price is this, its rating is this," a machine can read that label directly without having to reinterpret the body text.

This label is invisible to human eyes and sits hidden in the page's code, so it doesn't affect how the page looks, while still helping search engines or AI services quickly grasp what the page is about. For example, if an online store adds this label to every product page, search results can show star ratings or prices right away, and AI systems answering questions can more easily find and use that page as a source.

However, since the page creator writes this label themselves, there's no way to tell from the outside whether the content matches the actual page or has been exaggerated — a real limitation of this approach.

1. Try copying and pasting this into a chatbot you commonly use:

Create JSON-LD structured data for a product page using this information: product name 'Wireless Earbuds', price $59, average rating 4.5, 120 reviews.

2. Looking at the resulting code, you'll notice the product name, price, and rating aren't written as human-readable sentences but organized into fixed fields and values. This is exactly the format used to hand information to machines while staying hidden inside a webpage.