Structured Data Tester Online — Free Structured Data Tester Tool

CodexFuse Team · 2026-11-06T06:14:09.675Z · 10 min read min read

Test your JSON-LD schema before Google does. Free structured data tester with per-type required-field checks, a score, and a worked recipe-schema fix.

A structured data tester is a free online tool that checks the JSON-LD schema markup on a page and tells you whether Google can actually read it. Paste your markup, and the tester validates the syntax, checks the required fields for the schema type, and gives you a score with a list of issues to fix. It takes seconds, and it catches the silent errors that keep your rich results hidden.

Structured data is the quiet workhorse of modern SEO. You can write the best product page on the internet, add perfect FAQ schema, and still get nothing in the search results — because one missing comma, one wrong field name, or one absent required property made Google ignore the whole block. The page looks fine to a human. To a search engine, it is broken. A structured data tester exists to close that gap before you publish, not after your rich results fail to appear.

What does a structured data tester actually check?

A structured data tester checks three things: whether your JSON-LD is valid JSON, whether it matches the schema type you claim, and whether it includes every field Google requires for that type. It parses the markup, flags syntax errors by line, verifies required and recommended properties, and reports a score so you can see at a glance how close the markup is to being eligible for rich results.

Most testers, including the Structured Data Tester on CodexFuse, work the same way. You paste a block of JSON-LD into the input box. The tool parses it in your browser, checks it against the rules for 12 common schema types — Article, Product, FAQ, Recipe, Review, LocalBusiness, Organization, Event, BreadcrumbList, HowTo, JobPosting and VideoObject — and returns a per-field verdict. A sample is included so you can see a passing result before testing your own markup.

The three layers of validation

• Syntax: is the JSON well-formed? A trailing comma or an unclosed brace invalidates everything, and this is the most common failure in hand-written schema.
• Structure: does the markup follow the schema type? A Product needs a name and an image; an FAQ needs a mainEntity list of Question objects with acceptedAnswer text.
• Eligibility: does it meet Google's requirements for rich results? Valid schema is not the same as eligible schema — Google requires specific fields for each rich result type, and missing one means no enhancement.

Why does broken schema cost you clicks?

Broken schema costs you clicks because rich results take up more space and earn more attention than plain blue links, and a single invalid property can silently disqualify a page from all of them. A product page without valid Offer markup never shows a price. A recipe page with a malformed HowTo never shows cooking time. The page still ranks, but it competes as a plain result against competitors with stars, prices and FAQ dropdowns — and users click the richer result first.

The damage is usually invisible. There is no error message on your site. Search Console will eventually flag the problem in its enhancements report, but that can take days or weeks after the page was crawled. By then the page has already served thousands of plain impressions that could have been rich ones. Testing before publishing is the only reliable way to catch it in time.

How do you test structured data in under a minute?

Open the free Structured Data Tester, paste your JSON-LD into the input box, and read the score. Fix every error the tool flags, re-paste, and repeat until the score is clean. Then paste the corrected markup into your page and publish. The whole loop takes under a minute for a single block, and it is the cheapest SEO check you will ever run.

A worked example: fixing a bakery's recipe schema

Here is a concrete case. A small bakery in Lahore runs a food blog. Its most popular post is a chocolate cake recipe that gets around 4,000 visits a month from Google, but the result has never shown a star rating, a cooking time or a calorie count — the rich result its competitors all display.

The owner pastes the page's JSON-LD into the structured data tester. The score comes back 62 out of 100, with three issues: the recipeYield field is missing, the aggregateRating block has a ratingValue of 4.8 but no reviewCount, and the nutrition object is missing the calories property Google wants for recipe cards.

She adds the three fields, re-tests, and the score reads 100. Before publishing she also runs the block through the schema validator as a second opinion — it confirms the markup is well-formed, so the tester score is the one to trust on completeness. She pastes the corrected block into the page and republishes. Two weeks later the recipe appears in search with stars, a 45-minute cook time and a calorie count. Nothing else on the page changed — no new backlinks, no rewritten copy. The only change was valid, complete schema. That is the whole point of testing: the fix is small, the visibility gain is not.

Which schema types should you test first?

Test the schema types that match the pages bringing you traffic. A business site starts with Organization and LocalBusiness, a shop with Product and Review, a publisher with Article and FAQ, and a food or how-to site with Recipe and HowTo. Testing a type you do not use wastes the effort — and adding schema for content that is not on the page is exactly the kind of markup Google penalises.

What are the honest limits of a structured data tester?

A tester validates markup; it does not validate truth. It will happily pass a five-star rating you invented, a price that does not exist on the page, or a recipe for a dish you never cooked. Google treats that as spam, and the penalty is losing rich-result eligibility across the site. The tool checks the shape of your data, not whether the data is honest.

It also cannot see the page. A tester reads the JSON you paste, not the live URL, so it cannot tell you whether the schema on your live page matches the schema you tested, whether your CMS stripped it out, or whether a caching plugin is serving an old version. After publishing, confirm the live page separately — run a free SEO audit or check the URL in Search Console's enhancements report a few days after the crawl.

How does structured data fit a managed platform?

Schema markup is a small file on a page, but keeping it correct touches hosting, the CMS, caching and deployment — four things that usually live in four different tools. On a managed platform the chain is shorter. Your pages, your schema and your deployments sit in one place, so a fix tested in the morning is live by lunch instead of waiting on a developer ticket, a plugin update and a cache purge.

Frequently Asked Questions

Is the structured data tester really free?

Yes. The tool is free and unlimited. You will need a free CodexFuse account to use it, but there is no per-test charge and no cap on how many blocks you validate.

What is JSON-LD?

JSON-LD is a format for writing structured data as a block of JavaScript inside your page. It is Google's recommended format because it sits separately from your visible content, so you can describe a product, article or recipe without changing how the page looks.

Does a 100 score guarantee rich results?

No. A perfect score means your markup is valid and complete, which makes the page eligible for rich results. Google still decides whether to display them, based on relevance, page quality and the query itself.

Can I test schema from a live URL?

This tester works on pasted JSON-LD rather than a URL. Copy the script block from your page's source, paste it in, and test. For a full-page check, follow up with a page audit or Search Console's enhancements report.

How many schema types does the tester support?

Twelve: Article, Product, FAQ, Recipe, Review, LocalBusiness, Organization, Event, BreadcrumbList, HowTo, JobPosting and VideoObject. Each has its own required-field checks.

What should I do if my score is low?

Fix the errors in the order the tester lists them, starting with syntax. Add the missing required fields, re-paste, and re-test until the score is clean. Then update the live page and request a recrawl in Search Console.

Test your schema before Google does

Every page you publish with untested schema is a gamble. Most of the time the markup is fine. Sometimes it is not — and the cost is weeks of plain, unremarkable search results while competitors show prices, stars and answers. A sixty-second test removes the gamble entirely.

Open the Structured Data Tester now, paste the JSON-LD from your most valuable page, and fix whatever it flags. Then move the site itself to a platform where the fix stays live: bring your hosting, business email, security and backups to CodexFuse, where everything is fully managed and you pay only for the credits you use. Start with your homepage schema today — test it, fix it, and watch what Google does with it next.