Schema Validator

Common markup errors and how to fix them

Nine things the validator catches most often. For each one, the broken code and the corrected version. Google silently skips most of these: the markup simply does not work, and nobody tells you.

1. Trailing comma

JSON is stricter than JavaScript: a stray comma before } or ] breaks the whole block. The browser does not complain; Google does not read the markup.

// before
{ "@type": "Organization", "name": "BB STUDIO", }

// after
{ "@type": "Organization", "name": "BB STUDIO" }

2. Single quotes

JSON allows only double quotes. Code with single quotes looks fine but does not parse.

// before
{ '@type': 'Article', 'headline': 'Title' }

// after
{ "@type": "Article", "headline": "Title" }

3. Missing @context

Without "@context": "https://schema.org" the parser does not know that Product is a Schema.org type rather than an arbitrary word. The whole block is ignored.

// before
{ "@type": "Product", "name": "Laptop" }

// after
{ "@context": "https://schema.org", "@type": "Product", "name": "Laptop" }

4. Comments inside JSON

A developer left // TODO or /* ... */, and it is no longer JSON. Comments must be removed entirely.

5. A required field is missing

For Article it is headline; for Product, name; for Event, name, startDate and location. Without them Google will not show a rich result even if everything else is perfect. The full table is below.

6. A rating with no reviews on the page

The most dangerous error: aggregateRating on a page where no review is visible. Google calls this self-serving reviews, and it is the most common reason for manual actions, which remove every rich snippet on the site, not just this one.

// before — on every page of the site
{ "@type": "Organization", "name": "...",
  "aggregateRating": { "ratingValue": "5", "reviewCount": "9" } }

// after — only on the page where reviews appear as text
{ "@type": "Organization", "name": "..." }

7. Price as a string with currency

"price": "9 900 UAH" is not a number. It should be "price": "9900" with a separate "priceCurrency": "UAH".

// before
"offers": { "@type": "Offer", "price": "from 9 900 UAH" }

// after
"offers": { "@type": "Offer", "price": "9900", "priceCurrency": "UAH" }

8. Date not in ISO 8601

The parser will not understand "datePublished": "12.09.2026". Correct is "2026-09-12", or with time and zone: "2026-09-12T10:00:00+03:00".

9. Markup that does not match the page

The code says 9,900; the page says 12,900. The code has five FAQ questions; the page shows three. Google compares markup with visible content, and a mismatch is penalised the same way as hidden text. Markup describes the page; it does not decorate it.

Required and recommended fields by type

The same rules the validator applies. Without required fields there is no rich result; recommended fields raise the odds of getting one.

Note for Product: aggregateRating is recommended, but only when the page genuinely shows reviews. Otherwise, see error 6.

After the check

"No errors" from the validator means the code is correct, not that Google will show stars or an FAQ in results. Rich results are Google's decision, and it decides differently for different sites and queries. What is up to you: the right type for the page's content, the required fields, markup that matches the text, and none of what is described in point 6.

For which markup types actually produce rich snippets in 2026, what gets them removed, and why LocalBusiness without an address is worse than no markup at all, read Schema.org structured data: what it gives and what loses it. Our markup generator builds correct JSON-LD for the typical cases — Organization, Article, FAQ, Product — so you do not have to write it by hand.