Structured Data Errors: How to Find and Fix Broken JSON-LD

Structured data is the one part of SEO where a mistake shows up straight away and in plain sight: the stars disappear from the search result, the price stops rendering, the product drops out of rich results. Rankings don't move, but the way your result looks in Google does. And that shows up in click-through rate.

Below is a rundown of the faults I hit most often on real sites, where you'll see them, and how to fix them so they don't come back.

What "broken" structured data actually means

There are three separate states here and it pays not to mix them up:

1. Invalid code — the JSON-LD can't be parsed at all. A missing brace, an unescaped quote, HTML that leaked into the JSON. Google ignores the whole block.
2. Valid code, missing required properties — the schema parses, but Google won't use it for a rich result because the required fields aren't there. A Product with no offers, for example.
3. Valid code that contradicts the page — the markup says €19, the page says €24. That isn't a technical bug any more, it's a policy breach, and it can lead to a manual action.

The third case is the nastiest, because no validator will flag it. You only find it by comparing the markup against what the page actually shows.

Where you'll see the errors

Rich Results Test

search.google.com/test/rich-results is the closest thing to what Google really sees. It tests one URL or a pasted snippet and tells you which rich result types the page is eligible for. Important caveat: it only tests types Google supports. Put Recipe on a services page and the test tells you nothing.

The test also shows the rendered HTML. That's where you check whether your JSON-LD made it into the page at all — a common problem with markup generated by JavaScript or injected through a tag manager.

Schema Markup Validator

validator.schema.org checks syntax and validity against the schema.org vocabulary, regardless of what Google does with it. I reach for it when Rich Results Test "found nothing" and I need to know whether the markup is broken or simply unsupported.

Search Console → Enhancements

This is the only source that works across the whole site rather than one URL. The Enhancements section lists the types Google found on your site — Products, Breadcrumbs, Articles. Each one comes with a list of errors and warnings, the number of affected URLs, and example pages.

One detail worth knowing: the data is processed with a lag, and the example list is not complete. If Search Console reports 1,200 pages with an error, it will show you a few dozen. You can infer the pattern from them, but not get the full list.

The faults I find most often

Two plugins generating the same type

A classic on WordPress and WooCommerce: the SEO plugin outputs Product, the theme adds its own microdata block, and a review plugin adds a third. Google then sees three products on one page, each with a different price or no offers at all.

The fix isn't "repair one of them", it's switching off two and keeping a single source of truth. In practice that means disabling schema either in the theme or in the SEO plugin, depending on which one carries the more complete data.

Price as text with a currency symbol

``json "offers": { "@type": "Offer", "price": "1 299,00 €", "priceCurrency": "EUR" } ``

This won't pass. price has to be a number: no currency symbol, no spaces as thousand separators, decimal point rather than comma. The currency lives in its own priceCurrency property in ISO 4217 form. Correct version:

``json "offers": { "@type": "Offer", "price": 1299.00, "priceCurrency": "EUR", "availability": "https://schema.org/InStock", "url": "https://example.com/product" } ``

The same logic applies to availability: it needs the full schema.org URL, not "in stock" or "Available".

Missing required properties

The usual suspects:

• Product without offers, review or aggregateRating — without at least one of those there's no rich result eligibility.
• Product in a merchant listing without image, or without sku/gtin/mpn.
• Article without headline or without image.
• BreadcrumbList where an item is missing position or name.
• LocalBusiness without an address that has its parts filled in.

Typical causes: products priced on request, variant products with a price range, or imported items with an empty field.

Invalid JSON

This happens whenever database text lands in JSON-LD without escaping. A product description contains quotation marks or a <br> and the whole block falls apart. The symptom: Rich Results Test says "No items detected" while you can clearly see the code in the page source.

The fix belongs in the template — escape the values and strip HTML tags out of the description.

Relative URLs

"image": "/wp-content/uploads/product.jpg" is a bug. Every URL in structured data has to be absolute, protocol included. Same goes for url, logo and item in a breadcrumb trail.

Dates in the wrong format

datePublished and dateModified have to be ISO 8601 — 2024-05-12 or 2024-05-12T09:30:00+02:00. 12/5/2024 is invalid. And dateModified shouldn't be today's date just because the page was generated today; if you didn't change the content, the date shouldn't move.

Markup Google no longer shows

Since 2023 Google has heavily restricted FAQ rich results — in practice you only see them for a narrow set of authoritative sites — and it stopped showing HowTo altogether. The markup isn't wrong, it just won't produce anything. If it's already on your site, leave it there, but don't expect a change in the SERP and don't do extra work for it.

The same applies to reviews a business writes about itself or its own products with no independent source. Google doesn't display those.

Markup that doesn't match the page

A cached price in JSON-LD while the page shows a promotional one. A rating of 4.9 from 218 reviews when the page has none. InStock on a sold-out product. These are the errors no validator will catch, and they can cost you more than missing markup would.

Error versus warning

Search Console separates Errors (red) from Valid with warnings (yellow). An error means the page isn't eligible for a rich result. A warning means it is eligible, but a recommended property is missing.

The work order is simple: errors first, on the templates covering the most URLs (category pages, product detail), then warnings where commercial data is involved — brand, sku, aggregateRating, shippingDetails. Warnings on old blog posts come last, or never.

One template fix usually resolves thousands of URLs. That's why fixing individual products by hand makes no sense — find the template that generates the error.

How to verify a fix

1. Fix the markup on one representative URL.
2. Run it through Rich Results Test. If the markup is built by JavaScript, test the URL, not a pasted snippet.
3. Deploy across the whole template.
4. In Search Console, hit Validate fix on the error. Google re-crawls a sample of URLs. It takes days to weeks depending on site size.
5. Watch whether rich results actually appear in the SERP, and compare CTR on the affected URLs.

That last step is the one people skip. The goal isn't a green tick in Search Console. The goal is a result that looks better in Google and gets clicked more often.

How I handle it

When I crawl a site, I check structured data on every page I pass through: whether the JSON-LD parses, whether the type matches the page content, whether required properties are missing, whether it's duplicated. For findings that can be fixed, I don't hand you advice like "add offers" — I write out the finished JSON-LD block with your data in it, ready to paste. You approve it and it goes live through the WordPress plugin, the API, or a CSV export.

After deployment I measure impact 28 days before and after, so you can see whether anything actually changed. The first crawl of a site takes roughly 3 minutes from the moment you enter the address.

What I don't promise: that fixing structured data will move your positions up. Structured data isn't a ranking factor. It changes how the result looks and therefore how often it gets clicked — and that's the reason to bother with it.

Summary

• Find errors in Search Console (whole site), verify them in Rich Results Test (single URL).
• Most common causes: two markup sources, price as text, missing offers, relative URLs, unescaped values.
• Fix the template, not individual products.
• The markup has to match what's visible on the page.
• Measure success on CTR and result appearance, not on positions.