What it does
Structured data is a block of JSON-LD in your page that tells search engines what the page is: an article, a product, an organisation. If that JSON has a single stray comma or quote, search engines can't read any of it.
This checker does one job. It tells you whether your JSON-LD parses as valid JSON, and if it doesn't, it shows the parser's error so you can find the mistake. It does not check your schema.org types or properties, and it can't tell you whether a page qualifies for rich results. For that, use Google's Rich Results Test or the Schema Markup Validator once the syntax is clean.
How to use it
- 1Copy the JSON from inside your script type="application/ld+json" tag. Paste only the JSON, not the script tags around it.
- 2Paste it into the Content box.
- 3Press Run.
- 4If you see Invalid JSON, read the error, fix that spot, and run it again. If you see Valid JSON, check your @type and required fields next.
The mistakes that break JSON-LD
Most broken structured data comes from a handful of small slips, often made while editing by hand or pasting from a word processor.
- A trailing comma after the last item in an object or list.
- Single quotes instead of double quotes around keys or values.
- Curly "smart" quotes pasted from a document editor.
- An unescaped double quote inside a text value, such as a product name with inches.
- Comments, which JSON doesn't allow.
- Template code that printed nothing, leaving an empty value like "price": ,
Valid JSON is the first step, not the last
Once it parses, check that each @type is a real schema.org type and that you've included the properties Google lists as required for the result you want. The markup should describe what's actually visible on the page. Marking up content people can't see goes against Google's guidelines.
Structured data makes a page eligible for rich results. It never guarantees them. Google decides per search whether to show one, and it has retired or narrowed several types over the years, such as HowTo results and FAQ results for most sites.
Questions
Does this check schema.org types and required fields?
No. It only checks that the JSON parses. Use Google's Rich Results Test to see which rich results a page can get, and the Schema Markup Validator to check schema.org types in general.
Is my markup sent anywhere?
No. The check runs in your browser with the standard JSON parser.
Will valid structured data get me rich results?
Not necessarily. It makes the page eligible. Google chooses whether to show a rich result based on the search, the page and its own policies.
Why does it say Invalid JSON when I paste my whole script tag?
The script tag is HTML, not JSON. Paste only what's between the opening and closing tags.
Is JSON-LD better than Microdata?
Google supports both and recommends JSON-LD because it sits in one block, separate from your HTML, which makes it easier to write and maintain.