Google’s rich results testing tool has been updated to include a selector for desktop or mobile so website owners can check their results on both platforms. This tool shows if pages are properly structured for display in Google’s carousels, images, breadcrumbs, events, books, and other types of rich snippets. A glossary is available with images showing what each type of result looks like with the proper structured data in place.
Last week Google announced that it will begin enabling mobile-first indexing (crawling sites with a mobile user-agent) by default for new domains on July 1, 2019. Site owners can select “Googlebot Smartphone” as the user-agent on the rich results testing tool to see if their sites are prepared for mobile-first indexing. The tool is still in beta, so not all rich results and error types are supported yet.
If your page supports rich results, you will see a confirmation and can click through to view the HTML. Certain rich result types will display a preview of how the result might appear in Google Search. If multiple result layouts are available, the tool will also let you drill down into the different layouts for both desktop and mobile.
If you get a result that says “Page not eligible for rich results known by this test” when you know that you have the structured data in place, it could be because the beta version of this tool only supports a subset of rich result types. These currently include job postings, recipes, courses, TV and movie, events, and Q&A pages.
You can also test your page using this tool by putting in a code snippet, in case your content is not publicly accessible or is restricted behind authorization.
Depending on your specific requirements, there are many different WordPress plugins that properly structure data to improve how your content appears in rich results around the web, such as Schema, All In One Schema Rich Snippets, Schema App Structured Data, Rank Math, and Yoast SEO, to name a handful of popular options.
Source: WP Tavern