What is Schema markup?

Schema markup, also called structured data, is a form of extra information you add to your website's HTML code. The purpose is to make it clear to search engines how your content fits together and what it's about. In other words, you help Google understand the pages the same way a person would interpret them. Schema markup is based on a shared vocabulary developed by Google, Bing, Yahoo and Yandex at schema.org – a standardised language that makes data machine-readable.

When you work with SEO, schema markup lets search engines "read between the lines". Instead of just registering text, Google can identify whether something is a product, an event, a person or a review. It becomes a kind of "meta description" that goes deeper than the classic meta title and description. Schema markup therefore works as a technical layer that improves the semantic understanding of your content – a central part of modern search engine optimisation, especially when you combine it with well-written, targeted content.

How do you use Schema markup?

You use schema markup by integrating small pieces of code, called scripts, directly into your page's HTML. There are several formats – Microdata, RDFa and the more widespread JSON-LD, which Google itself recommends. JSON-LD is easy to insert without changing the page's visible content. With it, you define which entities your page contains and how they relate to each other. For example, it could be an article with an author, a publication date and a rating.

A typical example of how to mark up product data in JSON-LD:

{
  "@context": "https://schema.org/",
  "@type": "Product",
  "name": "Example product",
  "description": "Short description of the product",
  "brand": "Example brand",
  "offers": {
    "@type": "Offer",
    "price": "299.00",
    "priceCurrency": "DKK",
    "availability": "https://schema.org/InStock"
  }
}

Here you clearly define what the search engine should understand: the product's name, brand, price and availability. When Google crawls the page, it recognises the structure and can show relevant information directly in the search result as rich snippets. That increases the chance of the user clicking, because the result looks more informative – an important part of your overall SEO strategy.

Why you should use Schema markup

Schema markup is an effective tool because it increases your visibility in the search results. By structuring your data, you help search engines show more relevant and detailed information under your result. That could be star ratings from reviews, product prices, stock status or event details. These so-called rich snippets attract more attention because they break up the otherwise uniform layout of the search results – and that often leads to higher click-through rates (CTR).

On top of that, you get a more robust digital presence. When you use schema markup together with strong content and a solid SEO strategy, you can get a greater return on your efforts in both search and paid ads. For webshops, it can mean customers already see price and stock status directly on Google. For brands, markup can ensure your logo and contact details are shown correctly in knowledge panels and across search surfaces, including voice search. That gives search engines the best starting point for presenting your brand accurately.

What types and variants are there?

At the time of writing, Schema.org contains hundreds of types and thousands of properties. You can choose from categories such as products, people, organisations, articles, events and reviews. Each type has its own fields you can fill in, depending on which information you want to highlight. That gives you the flexibility to tailor the markup to both your business's content and the formats Google supports.

Examples of different schema types:

Product: Name, price, brand, stock status and ratings
Article: Author, publication date, description and topic
Event: Date, location and ticket information
Organisation: Name, website and contact details

Even though there are many types, you should focus on the ones that make the most sense for your target audience and business goals. If you work with branding and strategy, it can add extra value to use markup for organisations and people, because it clarifies the relationship between the brand and key people.

How do you use Schema markup in practice?

In practice, you add schema markup either manually in your page's code or via tools such as Google's Structured Data Markup Helper. Here you simply highlight the relevant elements on the page, and the tool then generates the code for you. Afterwards, you can use Google's Rich Results Test or Search Console to check whether the data is being registered correctly.

A good approach is to start with the pages where markup has the biggest impact – typically product and category pages, blog posts or event pages. It's also important to keep track of how Google interprets your data over time. For example, you can follow the development in rich result impressions in Search Console and adjust the markup as needed. Together with ongoing SEO optimisation and performance analysis, it becomes a powerful tool for understanding what Google sees – and therefore how best to influence it.

What should you be aware of?

You should only implement schema markup for content that actually exists on the page. Search engines penalise markup if the data is misleading or manipulated. Google also recommends validating your code every time you change the structure, to avoid errors. You should also consider updating your markup when you change your website's structure or design – for example in connection with a major rebrand or a new digital strategy.

In other words, schema markup is a technical tool, but it only delivers real value when you use it actively together with good content, well-thought-out SEO and data-driven decisions. That way, you create a framework search engines can understand, which helps both Google and your users get the full benefit of your content.

Schema markup