What Is JSON-LD and Why Does It Matter?
JSON-LD is the format Google recommends for structured data markup. It sits inside a script tag in your HTML and tells search engines what your content is about — whether that is a product, an article, a recipe, an event, or a local business.
When your JSON-LD is valid and correctly implemented, Google can display rich results in search — star ratings, prices, FAQ dropdowns, event dates, and more. These enhanced results get significantly higher click-through rates than plain blue links.
When your JSON-LD is broken, none of that happens. Google either ignores the markup entirely or flags it in Search Console as an error.
Common JSON-LD Errors
Syntax errors are the most basic problem. JSON is unforgiving — a missing comma, an unclosed bracket, or a stray character breaks the entire block. Missing required properties prevent Google from generating rich results. Every schema type has required fields. For Product you need name. For Review you need reviewRating and author. Incorrect property values are common with dates (must be ISO 8601 format), ratings (must be numeric), and URLs (must be absolute, not relative). Mismatched content — where the structured data describes something different from what is on the page — can trigger a manual penalty. Nested entity errors occur when you embed one schema type inside another incorrectly.What the JSON Checker Finds
The AIPageSEO JSON Checker analyses every structured data block on your page and reports syntax errors with positions, missing required properties, invalid property value formats, deprecated schema types, content mismatches, and conflicting schema blocks.
How to Fix JSON-LD Issues
Always validate your JSON-LD with Google's Rich Results Test before deploying. Use a structured data generator to build your markup from scratch rather than editing raw JSON by hand. Keep your structured data in sync with your page content — if prices, dates, or ratings change on the page, update the JSON-LD at the same time.