A schema validator is a tool, such as Google’s Rich Results Test or the independent Schema.org Validator, used to check whether a webpage’s structured data markup is correctly formatted and eligible for relevant rich results.
Regularly validating structured data helps catch implementation errors before they prevent a page from qualifying for intended rich results, or worse, cause a search engine to disregard structured data entirely due to formatting issues.
Validating schema after any significant site update or template change is an important quality control step, since even small coding errors can break structured data across many pages simultaneously.
Schema validation is a standard part of our Technical SEO service.