Schema markup validator

A schema markup validator reads the structured data on a page and tells you two things: whether it is written correctly, and whether it meets the rules a search engine sets for a rich result. This one extracts every JSON-LD block from a URL or from code you paste, reports syntax errors by line and column, and checks each item against Google’s required and recommended properties. Use it as a quick structured data testing tool while you write or fix markup.

What does a schema markup validator check?

It checks three layers. First, whether each JSON-LD block is valid JSON. Second, whether each item declares a schema.org @context and @type. Third, whether the properties Google requires for that type are present and use usable values, such as ISO 8601 dates and numeric prices.

It also flags values that are present but wrong: a price written as “$19.99” instead of 19.99, a datePublished in a local date format, a rating outside its scale, an event with only an online location, or a job posting whose validThrough date has passed. Nested items are checked in place, so an Offer inside a Product and a BreadcrumbList attached to a WebPage are validated too. If the terms are new, start with structured data and JSON-LD.

Types and features covered

The rules follow Google Search Central’s structured data documentation as checked in November 2026. Types outside this table are still checked for syntax and value formats.

Google says FAQ rich results stopped appearing in Google Search in May 2026, after being limited to well-known government and health sites since August 2023 (Search Central changelog). The markup is still valid schema.org, so the validator checks it and labels it as retired instead of calling it an error.

How to read the results

Each item gets a card with its type, the Google feature it maps to and a list of findings, most serious first.

• Error: a required property is missing or its value cannot be used. The item is not eligible for its feature until you fix it.
• Warning: something is likely wrong or will limit the result, such as an expired price or ratings a business publishes about itself.
• Notice: a recommended property is missing, or a value could be more precise, such as a time without a timezone offset.
• Pass: every required property is present.

“Meets Google’s required properties” means eligible, not guaranteed. Google says structured data enables a feature to appear but does not guarantee that it will (structured data guidelines). The extracted JSON-LD is shown at the bottom, pretty-printed, with a copy button for each block.

Fixes for the errors we see most often

1. Trailing commas and curly quotes. JSON allows neither. The syntax report points to the exact line; editors that “smarten” quotes are a frequent cause.
2. Prices with currency symbols. Put the number in price and the ISO 4217 code in priceCurrency: "price": "19.99", "priceCurrency": "USD".
3. Dates in local formats. Use ISO 8601, such as 2026-03-14 or 2026-03-14T09:30:00+01:00.
4. Authors as plain text. Use an object with a type, name and URL: {"@type": "Person", "name": "…", "url": "…"}.
5. Ratings on your own business. Review snippets are not shown for reviews an organization publishes about itself. Mark up ratings on the product or service customers actually reviewed.
6. Breadcrumb gaps. Positions start at 1 and rise by one, and every crumb except the last needs an item URL.

How it works, and where it stops

For a URL, the validator fetches the HTML once, without running JavaScript, and reads every application/ld+json script, including items inside @graph and references made with @id. Pasted content can be a single JSON-LD object or a full HTML page. Microdata and RDFa are counted but not validated.

Two limits matter. Structured data injected by JavaScript is not in the HTML we fetch; Google renders JavaScript, so paste the rendered HTML from your browser’s developer tools to check it. And the property rules cover the types in the table above. Our view: fix markup here, then confirm with Google’s Rich Results Test before release, because Google’s own tool reflects rule changes first.

Structured data is one input among many. To see it next to crawlability, titles and AI crawler access, run the free SEO audit, and use the robots.txt tester to confirm Googlebot can reach the pages you marked up. The rich results glossary entry lists which features still exist.