What is a schema markup checker?
It is a tool that reads the structured data on a page and reports whether it meets schema.org syntax rules and search engine requirements. It finds missing required properties, malformed values and typos that stop your markup from producing rich results.
Why does validator.schema.org say my document is larger than 2.5 MB?
The official validator uploads your whole document to its server and rejects anything over 2.5 MB. This checker parses the document locally in your browser, so there is no size limit at all. You can also paste just the JSON-LD block instead of the full page.
Is this a Google structured data validator?
It is an independent tool that checks your markup against Google’s published required and recommended properties for each type. It is not operated by Google. For final confirmation of a specific URL, pair it with Google’s Rich Results Test and Search Console.
Can I check schema markup without a public URL?
Yes. Paste the JSON-LD or the page’s full HTML source, or upload a file. This lets you check staging sites, password-protected pages, local builds and drafts — none of which a URL-only validator can reach.
Does it support Microdata and RDFa?
Validation covers JSON-LD, the format Google recommends. When you paste an HTML page the tool also detects and reports how many Microdata and RDFa elements are present, so you know they exist, but it does not validate those formats property by property. If you are still on Microdata, migrating to JSON-LD is the recommended fix.
What are the most common schema errors?
In practice: prices written with a currency symbol or thousands separator, dates in dd/mm/yyyy instead of ISO 8601, a misspelled @type, missing image on Product, aggregate ratings with a review count of zero, relative image URLs, and duplicate conflicting Organization blocks from a theme plus an SEO plugin.
How often should I check my structured data?
Check every template once when markup is first added, again after any CMS, theme or plugin update, and whenever Search Console reports a new issue. Templated markup fails in bulk, so one broken template can affect thousands of URLs at once.
Will fixing these errors get me rich snippets?
Valid markup makes a page eligible for rich results — it does not guarantee them. Google still weighs content quality, policy compliance and query intent. Errors, however, do guarantee that no rich result appears, so clearing them is a necessary first step.
Does checking schema markup improve rankings?
Structured data is not a direct ranking factor. Its value is indirect but real: richer results occupy more space and attract more clicks, and clearer entity signals help search engines and AI answer engines understand and cite your content.
Do I need coding knowledge to use it?
No. Paste your code or a URL and read the report — every message names the property and describes the fix in plain language. If you would rather not edit JSON by hand, generate a clean replacement block with the schema generator and paste it over the old one.
Can I check a whole website at once?
This tool checks one page or one code block at a time, which is the right level for debugging a template. For site-wide monitoring, check one representative URL per template type here, then use Search Console’s Enhancements reports to track issues across all indexed pages.
Is my data sent anywhere?
No. Checking is entirely client-side JavaScript. The only time data leaves your browser is if you use the optional “Check a live URL” box, which requests that public URL through a proxy.
