Does this replace the Rich Results Test?

No. It catches syntax and structure problems instantly in the browser. Google’s tool adds eligibility checks that only Google can run.

What is the most common failure?

A trailing comma or an unescaped quote, which breaks the entire script tag with no visible symptom.

Why check required fields?

Missing required fields are the main reason valid-looking markup earns no rich result at all.

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JSON-LD validator

Paste a JSON-LD block. The tool checks the JSON parses, the context and type are present, and the required fields for Article, FAQPage, Product and BreadcrumbList are there.

What gets checked

The JSON parses: one trailing comma kills the whole block.
@context and @type are present.
Required fields per type: an Article needs a headline, a Product needs offers, a BreadcrumbList needs itemListElement.

This is a lint pass, not Google’s validator. It catches the mistakes that make markup silently invalid before it ever reaches a crawler.

JSON-LD validator

What gets checked

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