JSON-LD Validator - Online Structured Data Syntax Checker

JSON-LD (JavaScript Object Notation for Linked Data) is Google's recommended format for structured data markup. It allows you to embed machine-readable metadata in your web pages using a simple JavaScript-like syntax inside <script type="application/ld+json"> tags. Unlike Microdata or RDFa, JSON-LD doesn't require modifying your HTML elements — you simply place it in the page head or body. It helps search engines understand your content better, enabling rich results like product carousels, review stars, FAQ accordions, and knowledge graph panels, which can significantly improve click-through rates.

You can validate JSON-LD in several ways: 1) Use this free online validator — paste your code and get instant syntax checking with error line numbers. 2) Google's Rich Results Test — checks if your markup qualifies for Google rich results. 3) The Schema Markup Validator (formerly Google Structured Data Testing Tool) — validates against Schema.org specifications. We recommend using both this tool for quick syntax checks and Google's Rich Results Test for final verification before deploying to production.

Common JSON-LD mistakes include: Missing or invalid @context — must be "https://schema.org"; Trailing commas after the last property in an object or array (not valid in JSON); Unquoted property names — all keys must be double-quoted; Using single quotes instead of double quotes for strings; Missing @type — while technically optional, omitting @type often prevents rich result eligibility; Incorrect nesting — e.g., putting an address string where an address object with @type is expected; Comment syntax — JSON doesn't support // or /* */ comments. Always validate before publishing.

The @context property defines the vocabulary used in your structured data. For SEO purposes, you should almost always use "https://schema.org" (or the older "http://schema.org"). This tells search engines that your property names follow Schema.org definitions. You can also use an array of contexts if you're mixing multiple vocabularies, or an inline object to define custom terms. However, for Google rich results, stick with the standard Schema.org context. Without a valid @context, your JSON-LD is just plain JSON — not linked data.

Yes, absolutely! You can include multiple <script type="application/ld+json"> blocks on a single page. Each block should contain a complete, self-contained JSON-LD object. Alternatively, you can use a JSON array with the @graph keyword to combine multiple entities in one script block. Both approaches are valid and supported by Google. Common examples include having separate blocks for BreadcrumbList, Product, Organization, and Article on the same page — each describing different aspects of your content.

Google supports a wide range of Schema.org types for rich results, including: Article (NewsArticle, BlogPosting), Product (with offers, reviews), LocalBusiness (and subtypes like Restaurant, Store), Organization, Person, Event, Recipe, FAQPage, HowTo, BreadcrumbList, VideoObject, Review, JobPosting, Course, and more. For the complete and up-to-date list, refer to Google's Search Gallery. Not all Schema.org types trigger rich results — Google decides based on the type, completeness, and quality of your markup.

All three are structured data formats, but they differ in implementation: JSON-LD is a standalone JavaScript block injected into the page — it's separate from your HTML markup, making it easy to add, update, and maintain without touching your templates. Microdata uses HTML attributes (itemscope, itemprop, itemtype) directly on existing elements, which can clutter your markup. RDFa is similar to Microdata but uses different attributes (vocab, typeof, property). Google recommends JSON-LD for most use cases because it's cleaner, less error-prone, and easier to manage with modern JavaScript frameworks and tag managers.