What is Schema Markup?
A vocabulary of structured data tags that tell Google what each piece of content on your page means — improving rich-result eligibility and AI citability.
Also known as: structured data, schema.org, JSON-LD
Schema markup is a standardized vocabulary maintained at Schema.org that lets you mark up content on your page with explicit meaning. Instead of Google having to guess that a phone number on your page is your business's phone number, schema lets you tell it directly.
The most common implementations are: LocalBusiness (or a specific subtype like Plumber, HVACBusiness, Dentist) for the homepage, Service schema for each service offering, FAQPage for FAQ sections, Article for blog posts, and Review or AggregateRating for testimonials.
Schema is invisible to users — it lives in the HTML as JSON-LD scripts. But it's a strong signal to search engines and a major contributor to rich-result eligibility (the star ratings, FAQs, and event details that appear in search results). It's also increasingly used by AI sources (ChatGPT, Perplexity, Google's AI Overviews) to determine which businesses to cite.
Schema is the cheapest, highest-leverage SEO improvement most sites can make. It usually takes a few hours to implement and unlocks rich-result placements and AI-source citations.