Free Schema Markup Validator - Check Your JSON-LD Structured Data Instantly
Paste your schema markup or full page source and get a plain-English breakdown of every error, warning, and missing field - checked against Google's rich result requirements for 15+ schema types. Nothing leaves your browser.
Checked Against Schema.org & Google's Structured Data Guidelines
What Is a Schema Markup Validator?
A schema markup validator is a tool that checks your JSON-LD structured data for two things: whether the code is technically valid, and whether it includes the fields Google and schema.org expect for that content type. This tool does both, entirely inside your browser - no schema is ever uploaded to a server or checked against a remote database.
It's not a replacement for Google's Rich Results Test - that's the only tool that confirms actual rich-result eligibility on a live, indexed page. Instead, this validator is what you run before publishing, so you catch missing required fields and malformed JSON early, in seconds, without waiting on a crawl.
Validator vs. Rich Results Test
This validator: instant, offline, checks syntax + required/recommended fields for 15+ types, unlimited runs while you edit.
Google's Rich Results Test: the authoritative source for whether a specific live page actually qualifies for a rich result today.
Check Your Schema Markup in 3 Steps
No account, no rate limits, no data leaving your machine - the validator runs entirely in JavaScript in your browser.
Paste Your Markup
Drop in a JSON-LD snippet, or paste your full page's HTML source and let the tool find every schema block for you.
Run the Check
Every block is parsed and checked for valid JSON, a correct @context/@type, and Google's required + recommended fields for that type.
Read the Verdict
Get a plain-English list of errors, warnings, and passed checks - grouped per schema block, with the exact field names to fix.
Fix & Re-Validate
Edit the markup in the box and hit Validate again. Once it's clean, paste it into your page's <head> with confidence.
Schema Types This Validator Understands
Structural checks apply to any JSON-LD. These types also get field-level required/recommended checks based on Google's structured data guidelines.
Why Validate Before You Publish
Catches Errors Before Google Does
A single missing required field can disqualify an entire page from rich results. Catch it in seconds, not after a Search Console crawl report.
Nothing Ever Leaves Your Browser
No server round-trip, no third-party tool, no request logs - every field, type, and required-property check runs client-side in JavaScript, so unpublished or client-confidential markup stays private.
Faster Than a Round Trip
No queueing, no waiting on a remote testing tool - validate as many times as you want while you iterate on the markup.
Frequently Asked Questions
Does this replace Google's Rich Results Test?
No. This tool catches JSON-LD syntax errors and checks your markup against schema.org and Google's documented required/recommended fields, but only Google's own Rich Results Test and Search Console can confirm actual eligibility for rich results on live, indexed pages.
How does a schema validator work without sending data to a server?
The rules for what each schema type needs are built directly into this page as JavaScript, based on schema.org's vocabulary and Google's public structured data guidelines. Your markup is parsed and checked in your browser - no data is ever sent to a server or third-party service.
Can I validate multiple schema blocks at once?
Yes. Paste a full page's HTML source and the tool automatically extracts every <script type="application/ld+json"> block - including multiple types combined with @graph - and validates each one separately.
What's the difference between an error and a warning?
Errors are things that break the markup outright - invalid JSON, a missing @type, or a field Google lists as required for that type. Warnings are recommended-but-not-required fields; leaving them out won't invalidate the schema, but filling them in improves your rich result eligibility.
What is JSON-LD structured data used for?
JSON-LD structured data describes the content on a page in a machine-readable format based on schema.org. Search engines use it to power rich results like star ratings and FAQ dropdowns, and AI systems use it to understand and cite page content more accurately.
I don't have schema markup yet - where do I start?
Use the Free Schema Markup Generator to build clean JSON-LD for 16 schema types first, then run it through this validator before publishing.
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Need Schema Rolled Out and Validated Across Your Whole Site?
Our technical SEO team can implement, test, and monitor structured data across every template - not just one page at a time.