Who is JSON-LD Tester & Agent Inspector for?

JSON-LD Tester & Agent Inspector is a B2B product built for technical SEOs, web developers, agencies, and SaaS teams.

Is JSON-LD Tester & Agent Inspector free?

Yes — JSON-LD Tester & Agent Inspector is free to use.

What platforms does JSON-LD Tester & Agent Inspector run on?

JSON-LD Tester & Agent Inspector runs on the web and embeddable surfaces.

Is JSON-LD Tester & Agent Inspector still active?

Unverified. JSON-LD Tester & Agent Inspector has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.

Who develops JSON-LD Tester & Agent Inspector?

JSON-LD Tester & Agent Inspector is developed by DevAd.

How long has JSON-LD Tester & Agent Inspector been around?

JSON-LD Tester & Agent Inspector first shipped in 2026.

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JSON-LD Tester & Agent Inspector

Name: JSON-LD Tester & Agent Inspector
Author: DevAd

mozilla.orgBrowser DevTools & extensions

JSON-LD Tester & Agent Inspector is a Firefox extension for inspecting and validating JSON-LD, Schema.org, Microdata, and RDFa on websites. It also checks HTTP headers, SEO signals, and experimental WebMCP agent tools locally for developers, technical SEOs, agencies, and SaaS teams.

FreeWebEmbeddable

JSON-LD Tester & Agent Inspector preview

Visit mozilla.org

Overview

12 features

In the Browser DevTools & extensions space, JSON-LD Tester & Agent Inspector takes a focused approach. It focuses on inspecting and validating structured data, SEO signals, and web agent tools without uploading site data. JSON-LD Tester & Agent Inspector is a B2B product aimed at technical SEOs, web developers, agencies, and SaaS teams. JSON-LD Tester & Agent Inspector costs nothing to use. JSON-LD Tester & Agent Inspector is available on the web and embeddable surfaces.

Behind JSON-LD Tester & Agent Inspector is DevAd, and it first shipped in 2026. Among its 12 catalogued features are JSON-LD detection, schema validation, and tree view. The interface is available in 32 languages, including Czech, German, and Greek.

Summary written by a language model from the project’s public pages.

JSON-LD detection
Schema validation
Tree view
Raw JSON view
Syntax highlighting
Parse errors
Schema.org links
Canonical checks
Robots checks
Microdata detection
RDFa detection
WebMCP inspection

Built with & integrations

Runs on

BrowserEmbeddable

Trust & compliance

Verified signals

HTTPSPrivacy Policy Terms of ServiceFree tierMulti-languageStore-verified publisher

Legal

Indexing history

What PulseGate has recorded for this listing

Indexed18 Sep · 16:02 UTC
JSON-LD Tester – Inspektor für strukturierte Daten verified via Firefox Add-ons
Source: Firefox Add-ons · Open

Frequently asked questions about JSON-LD Tester & Agent Inspector

What does JSON-LD Tester & Agent Inspector do?: JSON-LD Tester & Agent Inspector focuses on inspecting and validating structured data, SEO signals, and web agent tools without uploading site data. It is catalogued under Browser DevTools & extensions on PulseGate.
Who is JSON-LD Tester & Agent Inspector for?: JSON-LD Tester & Agent Inspector is a B2B product built for technical SEOs, web developers, agencies, and SaaS teams.
Is JSON-LD Tester & Agent Inspector free?: Yes — JSON-LD Tester & Agent Inspector is free to use.
What platforms does JSON-LD Tester & Agent Inspector run on?: JSON-LD Tester & Agent Inspector runs on the web and embeddable surfaces.
Is JSON-LD Tester & Agent Inspector still active?: Unverified. JSON-LD Tester & Agent Inspector has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.
Who develops JSON-LD Tester & Agent Inspector?: JSON-LD Tester & Agent Inspector is developed by DevAd.
How long has JSON-LD Tester & Agent Inspector been around?: JSON-LD Tester & Agent Inspector first shipped in 2026.
What languages does JSON-LD Tester & Agent Inspector support?: The interface is available in 32 languages, including Czech, German, and Greek.

At a glance

Pricing: Free
Platforms: Web
First seen: 18 Sep 2026
Built for: technical SEOs, web developers, agencies, and SaaS teams
Model: B2B
Solves: Inspecting and validating structured data, SEO signals, and web agent tools without uploading site data.

Registered as

Firefox Add-ons: json-ld-tester-agent-inspector

Developer

DevAd

Index record

Indexed: 18 Sep 2026
Lifecycle: Alive
First seen: Sep 2026
Last seen: 18 Sep 2026

Identity audit (13)

Slug: json-ld-tester-inspektor-fur-strukturierte-daten-mozilla-org
Lifecycle state recorded: 18 Sep 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 18 Sep 2026
Timeline basis: Indexed-at chronology (no inferred launch/funding milestones).
Name from: Derived from the project's own page and URL.
Category from: Assigned by a language model.
Summary from: Written by a language model from public pages.
Languages from: Detected by a language model, checked against the page's own declaration.
Last updated: 18 Sep 2026
Canonical URL: https://addons.mozilla.org/en-US/firefox/addon/json-ld-tester-agent-inspector

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