Schema Validator

A schema validator (or schema checker) is a tool that checks that a page's structured data, written with the Schema.org vocabulary, is properly formed and readable by search engines and AI. The official validator, the Schema Markup Validator, is free and available at validator.schema.org.

What is Schema.org?

Schema.org is a shared vocabulary, maintained by Google, Bing, Yahoo and Yandex, used to describe a page's content in a structured way: a business, an article, a product, an event, a FAQ. This markup, most often written in JSON-LD, helps search engines understand exactly what a page contains. It can trigger rich results (reviews, prices, FAQ, breadcrumbs) and also serves as a reliable source for generative AI when it cites a brand.

How to use the Schema Markup Validator

1. Go to validator.schema.org.
2. Paste the URL of the page to test, or switch to the code tab to paste your JSON-LD directly before publishing.
3. Run the test: the tool lists every Schema.org type detected on the page (Organization, Article, BreadcrumbList...).
4. Open each type to read the errors, which prevent the markup from being read, and the warnings, which point to missing recommended properties.
5. Fix the markup, republish, then run the test again until no errors remain.

Schema validator or Google Rich Results Test: which one to use?

The two tools complement each other. The Schema Markup Validator checks all of your markup against the Schema.org vocabulary, whatever the type. Google's Rich Results Test only checks the types that can trigger a rich result in Google, using Google's own rules.

If you are looking for a "Google schema validator", it is normal to feel lost: Google's old Structured Data Testing Tool was retired in 2021. Its validation side moved to validator.schema.org, and Google kept the Rich Results Test. To monitor your markup's validity across the whole site over time, the Google Search Console reports take over.

The most common errors

• Missing required property: for example, an Article without an author or a publication date.
• Wrong value format: a date that does not follow the ISO 8601 format, a price written with the currency symbol.
• Invalid JSON: one extra comma or one missing quotation mark is enough to make the whole block unreadable.
• Marked-up content missing from the page: marking up a FAQ or reviews that do not actually appear on screen goes against Google's guidelines.
• Duplicate schemas: two Organization or two BreadcrumbList blocks on the same page that contradict each other.

Validating your structured data on Webflow

On Webflow, JSON-LD goes in the page settings (custom code in the head), or in an embed inside a CMS template to generate dynamic markup for each post or item. Always test the published URL, not the Designer preview, since that is the one Google reads. To understand the vocabulary used, see our definition of Schema.org.

Frequently asked questions

Is the Schema Markup Validator free?

Yes, the tool is completely free, with no account and no limit on tests.

What is the difference between a schema checker and the official Schema.org validator?

"Schema checker" is a generic term for any tool that checks markup, including browser extensions. The official Schema.org validator remains the reference, because it checks the markup directly against the official vocabulary.

Why validate your structured data?

Invalid markup is simply ignored: the page loses its chance of getting a rich result, and AI has less reliable information about your brand. Validating after every change keeps you from losing that benefit without noticing.

To go further, find out how to monitor your pages with Google Search Console, or discover our SEO support for Webflow sites.