Schema, also called structured data markup, enhances search results through the addition of rich snippets. For example, you can add star ratings or prices for your products. As I explained in my previous blog post about technical SEO, adding schema by itself is not an SEO factor, but it is recommended by Google and indirectly helps your website improve rankings and increase page visitors.
How to Add Schema via WordPress Plugin
If your website is hosted on WordPress, you can use the Schema plugin to add structured markup to your pages. This plugin uses JSON-LD, which is recommended by Google and also supported by Bing.
How to Add Schema Manually
If you don't run a WordPress website or don't wish to rely on a plugin, you can manually add schema with a few more steps. Schema is usually added to the page header, although it's possible to add it to the body or footer as well. Some recent WordPress themes include specific text blogs to add schema to the body.
Note that adding schema through Google Tag Manager is not recommended. If you use Google Tag Manager, the structured data will be hidden within a container, making it difficult for Google's algorithms to read and give it appropriate weight.
To add schema manually, first, use a tool like MERKLE to generate the baseline markup. Although this is already fine to use as is, you can paste the baseline markup in a text editor and continue to edit and customize the structured data for each page.
If needed, you can insert additional properties that were not available on MERKLE.
How to Add html Strings to Schema
You can also add certain basic html strings to your schema markup, for example, if you'd like to include a bulleted list or hyperlink. An important thing to remember here is to escape double quotes when writing html, and simply replace them with single quotes.
Google Search displays the following HTML tags; all other tags are ignored: <h1> through <h6>, <br>, <ol>, <ul>, <li>, <a>, <p>, <div>, <b>, <strong>, <i>, and <em>
How to Validate Schema
You can use Google's Rich Results Testing Tool to make sure that your schema markup is being read properly, and Structured Data Testing Tool to actually see all of the structured data on the page. The final step will be to request indexing for the page that you added markup, via Google Search Console. Within a few days, you should see your markup under the enhancements sidebar.
The instructions above should serve as a guideline regardless of what kind of schema markup you are adding.
Note that in June 2021, Google has limited FAQ rich results to a maximum of 2 per snippet, so your snippet real estate may be a bit smaller. If you have 3 or more FAQs marked up, Google will show the 2 that are most relevant to the search query.