Support
Or browse existing questions at the issue tracker. Responses are usually within a few business days.
What the extension does
JSON-LD & Agent Inspector inspects, validates and tests structured data and agent tools on any website, for technical SEOs, web developers and agencies. Everything runs locally; nothing is uploaded.
- Detect and validate JSON-LD (plus Microdata & RDFa), with per-block errors and schema.org links.
- On-page SEO: meta tags, headings, Open Graph & Twitter, images, links, word count.
- Share previews for Facebook, LinkedIn, X, WhatsApp and Slack, plus hreflang validation.
- dataLayer inspection: GA4 events, Consent Mode v2, personal-data warnings, a cross-check against the page’s JSON-LD, and local snapshots you can diff.
- HTTP response headers and indexability for the current page.
- Agent tools (WebMCP) inspection with a safe manual tester and risk classification.
- Agent readiness score with llms.txt / robots.txt / sitemap / ai.txt checks.
Getting started
- Open a page that contains structured data (for example, a product or article page).
- Click the extension’s toolbar icon to open it.
- Browse the tabs: Structured Data, On-Page, Headers, dataLayer, Agent Tools and Readiness.
- Use the report button to produce a print-ready inspection report (saved locally as PDF).
Support the project
The extension is free and privacy-friendly. If it helps your work, you can support ongoing development:
Frequently asked
Does it send my data anywhere? No. See the Privacy Policy: nothing is uploaded and there is no tracking.
Why does a tab sometimes show “allow access”? The extension reads a page only on demand and asks for access per site; it does not run in the background on every page you visit.
Which browsers are supported? Safari, Google Chrome (and Chromium browsers) and Mozilla Firefox.
Does the dataLayer tab change my tracking? No. It reads window.dataLayer (and digitalData, adobeDataLayer, utag_data, …) once, read-only. dataLayer.push is never wrapped or replaced, so no page behaviour changes and no extra events are triggered. Events fired after the read appear once you click “Read again”.
Why does the dataLayer tab warn about personal data? Sending e-mails, phone numbers, IBANs or card numbers to Analytics/Ads is not allowed. Findings name only the path of the value, never the value itself, and every export (clipboard, PDF report, saved snapshot) is masked before it leaves the panel.
Where are dataLayer snapshots stored? Only in your browser’s local extension storage, only when you click “Save snapshot”, masked, and capped at 50 snapshots. Nothing is uploaded; “Delete” removes them.