What is schema markup (JSON-LD)?

Schema markup is a small block of structured data that tells search engines and AI exactly what a page is about: this is a Product with this price, this is an Article by this author. SuperSchema writes it in JSON-LD, the format Google recommends, and it does not change how your page looks or slow it down.

Schema markup (also called structured data) is a small block of code that spells out what a page is about in a way machines can read without guessing. A human looking at your page sees a headline, a price, and a photo and understands "this is a product for sale." A machine sees a wall of HTML. Schema markup labels the important facts explicitly: this is a Product, its name is X, its price is Y, its rating is Z. SuperSchema writes that block for you in JSON-LD, the format Google recommends, and it never changes how your page looks or how fast it loads.

The labels come from a shared, public vocabulary called schema.org, maintained by Google, Microsoft, and others. Because everyone agrees on the same terms (Product, Article, FAQPage, Organization, LocalBusiness, and hundreds more), a search engine or an AI assistant can read your markup and know exactly what each fact means, the same way it reads every other site that uses the vocabulary.

A quick example #

Say you have a page for a recipe. A person reads the title and the ingredient list and understands it instantly. Structured data hands the same facts to a machine as clearly labeled data:

json

{
  "@context": "https://schema.org",
  "@type": "Recipe",
  "name": "Classic Margherita Pizza",
  "author": { "@type": "Person", "name": "Jane Doe" },
  "prepTime": "PT20M",
  "recipeIngredient": ["Flour", "Tomatoes", "Fresh mozzarella", "Basil"]
}

Nothing here is new information: it all comes straight from what is already on the page. The markup just states it plainly so a machine does not have to infer the recipe name, the author, or the prep time from the surrounding layout.

Why it matters for AI and search #

Search engines and AI answer engines both work better when they are certain about your facts. When your page carries accurate schema, you make two things possible:

Rich results in search: Google can show enhanced listings (star ratings, prices, FAQ dropdowns, recipe cards) instead of a plain blue link. These come from the structured data on your page.
Accurate AI answers and citations: When an AI assistant like ChatGPT, Perplexity, or Google’s AI overviews answers a question, it is safer for it to state and cite a fact it can read explicitly than one it has to guess from raw HTML. Clear schema reduces the chance AI describes you wrong or reaches for a competitor instead.

Note Schema makes rich results and AI citations possible; it does not guarantee them. Search engines and AI systems decide what to show. Your job is to give them accurate, machine-readable facts so that when they do choose, they get you right.

Why JSON-LD, not microdata #

There are a few ways to write structured data. The two you will hear about are JSON-LD and microdata. SuperSchema uses JSON-LD, and so does Google’s official guidance. The difference is where the data lives.

JSON-LD: A single self-contained block of data, added inside a <script> tag in your page. It sits apart from your visible content, so it is clean to add, easy to read, and simple to update without touching your layout.
Microdata (older approach): Labels sprinkled throughout your HTML as extra attributes on the tags that hold your visible content. It works, but it tangles the data into your markup, which makes it fragile and harder to maintain: a redesign can quietly break it.

	JSON-LD	Microdata
Where it lives	One block in a <script> tag	Attributes woven into your HTML
Touches your layout	No	Yes
Easy to update	Yes, edit one block	No, spread across the page
Google’s recommendation	Recommended	Supported but not preferred

Tip Because JSON-LD is one self-contained block, you can add, update, or replace it without ever touching the rest of your page. That is why SuperSchema deploys it as a single script you paste into your page head.

Will it hurt or slow down my site? #

No. This is the most common worry, and the answer is a clear no on every count.

Schema is invisible to visitors. It does not change how your page looks or reads.
It has no meaningful effect on page speed. A JSON-LD block is a tiny amount of text that loads with the rest of your HTML.
It does not affect your normal search rankings negatively. Accurate structured data only helps machines understand content that is already there.

Warning The one real rule: schema must describe real, visible content on the page. Marking up a price or review that is not actually on the page is misleading, and search engines can penalize markup that does not match what visitors see. SuperSchema builds your schema from your actual page content, so it stays honest.

Do I have to write it by hand? #

No. Writing valid JSON-LD by hand means learning the schema.org vocabulary, picking the right type for each page, filling in the required fields, and keeping the syntax correct. It is doable, but it is fiddly and easy to get subtly wrong. SuperSchema does it for you.

SuperSchema reads the real content of your page: its headings, text, author, dates, prices, and questions.
It picks the schema type that fits the page (Article, Product, FAQPage, LocalBusiness, and so on) and can apply more than one when a page warrants it.
It fills in the fields from your actual content and produces valid JSON-LD.
It gives you a single script block to paste into your page head, or deploys it for you through an integration like HubSpot.

Note Each schema SuperSchema generates gets a schema quality score from 0 to 100 that grades how complete and detailed it is, so you can see at a glance whether a page is giving AI a thin sketch or a full picture. See how SuperSchema generates schema for the full workflow.

Tip Schema markup is one signal, not the whole story. For the bigger picture of how machines read a page, and where AI-readable files fit alongside schema, see how AI reads your website.