JSON-LD Tester & Agent Inspector by DevAd

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.