Should I use JSON-LD, Microdata or RDFa?
JSON-LD is the format Google recommends. It sits in its own script tag, so you can add or change it without touching the visible HTML, and it is easy to generate from a CMS or framework.
Will structured data improve my rankings?
Not directly. Structured data helps search engines understand the page and can make it eligible for rich results, such as product prices, ratings and breadcrumbs. Those can raise click-through rate, but Google decides when to show them.
Can I mark up content that is not visible on the page?
No. Google's guidelines require structured data to describe content users can see on the page. Marking up hidden reviews, prices or FAQs that are not shown can lead to a manual action that removes rich results for the whole site.
Can a page have more than one schema type?
Yes. A product page might include Product, BreadcrumbList and Organization. Put them in one script with an @graph array or in separate script tags. Both are valid.
Why are my rich results not showing after adding schema?
Valid markup makes a page eligible but does not guarantee rich results. Google has to recrawl the page, which can take days or weeks, and it may decide other results are more useful. Check the Enhancements reports in Search Console to see whether Google detected the markup and found any errors.
Which schema type should a homepage use?
Most homepages use Organization, or LocalBusiness for a business with a physical location, together with WebSite. Organization can include your logo, contact details and social profiles through sameAs, which helps search engines connect your site to your brand.