JSON-LD Tester & Agent Inspector Firefox

JSON-LD Tester & Agent Inspector

By: DevAd Add-on
Inspect and test JSON-LD, Schema.org data and agent tools on any website. On-page SEO, HTTP headers and an agent-readiness score — all local, nothing uploaded.

Features & Capabilities

Inspect, validate and test structured data and agent tools on any website — built for technical SEOs, web developers, agencies, and teams running shops and SaaS products. Everything runs locally; nothing is uploaded.

Structured Data • Detect all JSON-LD blocks, including @graph, arrays and nested types • Clear valid / warning / error status per block • Tree view and raw view with syntax highlighting and search • Precise parse errors with line and column • Copy JSON, copy the full <script> tag, or download • One-click links to the matching schema.org docs • Canonical and robots at a glance • Open the Google Rich Results Test or the Schema.org Validator with correct encoding — umlauts, accents, emojis and query strings are preserved • Complementary Microdata & RDFa detection

Agent Tools (experimental, WebMCP) • Detect agent tools a page exposes via document.modelContext • See each tool's description, input/output schema, and annotations • Automatic static analysis: naming, descriptions, schema issues, safety • Risk classification: Low / Medium / High / Critical • A safe manual tester that builds a form from the input schema and never runs destructive tools without explicit, multi-step confirmation

Agent Readiness Score • A local, transparent 0–100 score across structured data, tools, schemas, safety, testability and semantics • Prioritized High / Medium / Low recommendations • Checks agent & crawler conventions: llms.txt, robots.txt AI-crawler access, sitemap discovery, and the ai.txt AI-training opt-out

Privacy first • No visited URLs, page content or tool schemas are sent to any server • No ads, no tracking, no page modification • Minimal permissions: activeTab, scripting, storage, sidePanel

Available in English, German, Spanish, Italian and Chinese.

User Growth & Download Statistics

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Developed by:
DevAd
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/json-ld-tester-agent-inspector/

Is JSON-LD Tester & Agent Inspector Safe?

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

JSON-LD Tester & Agent Inspector does not require any sensitive permissions.

Risk impact analysis details
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

JSON-LD Tester & Agent Inspector is recently added, and hasn't been around long enough for us to gather enough data to accurately assess its risk level.

Risk likelihood analysis details
  • High This extension was recently updated in the past month. New updates may not be stable or safe.
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