SEOMarkup
Chrome Extension · v1.0.8 · MIT

Inspect structured data on any webpage.

DevTools makes you grep page source for application/ld+json. SEOMarkup just shows it — every block, parsed, searchable, copyable.

Add to Chrome — Free
3,000+ installs
Zero tracking
No account
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The problem

Reading schema in DevTools is a chore.

It works, technically. But the workflow is five steps, three tabs, and zero help when something's malformed.

Without SEOMarkup

5 steps
  1. 01 Open DevTools, switch to Elements
  2. 02 Cmd-F for application/ld+json
  3. 03 Copy the raw JSON from inside the <script> tag
  4. 04 Paste into a JSON formatter to make it readable
  5. 05 Paste again into Google's Rich Results Test. Repeat for every block.

And if it's malformed, DevTools won't tell you. The page still renders.

With SEOMarkup

1 step
  1. 01 Click the cat. Every JSON-LD block on the page renders as an interactive tree — searchable, copyable, one-click validateable.

Parse errors

Flagged with the broken snippet highlighted

Microdata / RDFa

Detected and labelled, not silently skipped

How it works

Three steps from install to inspection.

01

Install from Chrome Web Store

One click, no signup. Works on Chrome and any Chromium-based browser.

Installing SEOMarkup from the Chrome Web Store
02

Open any webpage

Your site, a competitor's, any URL. SEOMarkup runs on every http(s):// page.

Navigating to a website to analyse
03

Click the extension icon

Every JSON-LD block renders instantly as an interactive tree — searchable, copyable, validateable.

SEOMarkup showing structured data

Features

Everything in the popup. Nothing in the way.

No tabs, no validators, no source view. SEOMarkup reads the page and renders the structured data — that's it.

Interactive JSON tree

Every schema renders as an expandable tree. Collapse, expand, and drill into nested objects without squinting at raw JSON.

Full-text search

Type a property name, a value, or a URL. Highlights every match across every schema, with prev/next navigation.

Copy, download, validate

Copy as raw JSON or a paste-ready <script> tag. Download as .json. One-click open in Google Rich Results Test.

Parse error banners

Malformed JSON-LD flagged with the broken snippet shown

Microdata + RDFa

Non-JSON-LD formats detected and labelled, not skipped

Schema.org deep links

Click any @type to open its documentation

Zero network calls

Reads the active tab. Nothing leaves your browser.

Schema types

Every @type on Schema.org.

If the page declares it, SEOMarkup reads it. Click any type for its required fields and Google rich-result eligibility.

Not sure which types your site should use? Read the Schema.org cheat sheet →

Who uses it

Built for anyone who touches structured data.

Whether you audit client sites or just want to know what your CMS outputs, it fits into how you already work.

SEO Professionals

Audit client sites, reverse-engineer competitor schemas, validate before and after deploys. One tab, one click.

Web Developers

Debug malformed JSON-LD live on the page, verify @graph and nested structures, catch parse errors before they hit production.

E-commerce Managers

See the Product and Offer schemas your competitors declare. Reverse-engineer rich snippet eligibility without a separate tool.

Content Creators

Verify what your CMS actually generates. Catch broken Article or FAQ schemas before Google does.

Comparison

Why not just use DevTools?

Everything DevTools can't do for structured data, SEOMarkup does — for free.

Feature SEOMarkup Chrome DevTools
Instant JSON-LD display
Search within schemas
Copy as JSON or script tag
Download as .json
One-click validation link
Parse error detection
Microdata / RDFa detection
Schema.org deep-links
Zero tracking
No account required
Price Free Free

FAQ

Common questions.

What is JSON-LD structured data?
JSON-LD is a script block embedded in web pages that tells search engines what the content is: a product, an article, a business. Google uses it to generate rich results (star ratings, recipe cards, FAQ dropdowns) in search. SEOMarkup makes all of it visible in one click.
How do I see structured data on a website?
Install SEOMarkup, then click its icon on any page. It reads every <script type="application/ld+json"> block and renders them as an interactive tree — no DevTools, no source view.
Is SEOMarkup completely free?
Yes. No freemium tier, no trial, no credit card. Free forever. It's open source under the MIT licence — inspect the code on GitHub.
Does SEOMarkup track what websites I visit?
No. The extension uses only the activeTab permission, which reads the current page when you open the popup. It makes zero network requests. Your browsing data never leaves your browser.
What's the difference between JSON-LD, Microdata, and RDFa?
All three embed structured data in web pages. JSON-LD lives in a <script> tag and is Google's recommended format. Microdata and RDFa live inline in HTML attributes. SEOMarkup renders JSON-LD in full; it detects and labels Microdata and RDFa when present.
Does structured data improve Google rankings?
Not directly. But it makes your pages eligible for rich results — star ratings, FAQs, product prices — which typically get higher click-through rates. Read the full breakdown in the resources section.

More on structured data? Browse the resources →

SEOMarkup extension icon

Inspect schema on any page. One click.

Every JSON-LD block on any website, parsed and readable. Free, private, no account.

Add to Chrome — Free

No account · No tracking · Open source · MIT licence

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SEOMarkup in action — detecting and displaying JSON-LD schemas on a page
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