SEO Diagnostix

Technical SEO auditor: sitemap crawl, canonical, hreflang, links, robots, Schema.org, SERP & AI-GEO.

SEO Diagnostix: Detached Technical SEO Auditor & Visual Page Overlay Take full control of your technical SEO audits with SEO Diagnostix — a real-time page analyzer built for web developers, SEO professionals, and QA engineers. Unlike extensions that inject sidebars and clash with page CSS, SEO Diagnostix runs in a fully detached panel window. You get a clean, isolated interface to inspect search signals side-by-side at any viewport size, with zero layout interference. 🚀 Why Install SEO Diagnostix? Zero layout disruption — The audit panel lives in a separate window, so it never conflicts with the host page's CSS or DOM. Instant visual DOM overlays — Link audits draw colored overlays on the page so you can spot redirects and broken links in seconds. Sitemap Discovery & Crawl — Discover every sitemap from robots.txt, validate XML integrity, detect duplicate <loc> entries across locale sitemaps, and crawl hundreds of URLs with rate-limit-aware pacing. Smart lazy-loading checker — Image audits auto-scroll to trigger lazy-loaded assets before scanning. Real-time HTTP validation — Canonical, hreflang, link, sitemap, and image URLs are checked for real HTTP status codes. CORS-blocked responses are clearly marked Unverifiable — never falsely reported as success. One-click export — Full Markdown report for tickets, or a self-contained HTML report with collapsible sections, table-of-contents, SERP preview, AI/GEO detail, and Sitemap appendix — opens offline. 100% privacy & speed — No external servers, no tracking, no database. Everything runs locally in your browser. 🛠️ Exhaustive Feature Set 1. Overview & On-Page Metadata Meta title and description length checks (Google-aligned 120–160 char guidance for descriptions). Viewport, favicon, and meta keywords validation. Detects duplicate title/description and missing social tags. Keyword cross-check — When meta keywords are declared, verifies presence in title, H1, and URL. OG image validation — Checks reachability and recommended minimum dimensions (1200×630). 2. 🔗 Canonical & Hreflang Auditor Extracts all <link rel="canonical"> and <link rel="alternate" hreflang="..."> tags. Resolves relative URLs to absolute paths with normalized comparison (no false mismatches from trailing slashes). Verifies HTTP status codes and flags self-referential hreflang gaps. Recommends x-default hreflang when alternate locales are present but no fallback is defined. 3. 🟢 Progressive Link Auditor & Overlay Highlighter Scans all anchors in throttled batches to avoid rate-limiting. Internal vs external link breakdown in the audit summary. Page overlays: Green — Healthy links (2xx) Yellow — Redirects (3xx) Red — Broken links (404 / 5xx) Grey “Unverifiable” — CORS-blocked (status cannot be confirmed) Smart status cache for duplicate URLs. 4. 🖼️ Image SEO & Alt-Text Checker Auto-scrolls to force lazy-loaded images into view. Parses srcset for highest-resolution sources. Flags missing, empty, generic placeholder alt text, and broken image URLs. 5. 🤖 Robots & Directives Validator Parses <meta name="robots"> directives (noindex, nofollow, etc.). Fetches and analyzes robots.txt from the page origin on every audit. Warns on conflicts between meta robots and crawl rules. 6. Heading Structure & Content Outline Full H1–H6 outline with distribution stats. Detects missing/multiple H1s, empty headings, hierarchy jumps, and length issues. Inline badges on problematic nodes in the heading tree. 7. 📊 Structured Data & Schema.org Visualizer Detects and parses JSON-LD and Microdata (including multi-type @type arrays). Interactive schema instances with property checklists and validation warnings for Product, Article, Organization, BreadcrumbList, and more. 8. Google SERP Preview Live preview of how the page may appear in Google search results (title, URL, description). 9. 📱 Social Share Card Previewer Scans Open Graph and Twitter Card tags. Visual preview for Facebook, LinkedIn, and Twitter/X shares. 10. AI Retrieval & Extractability (GEO) Evaluates page signals relevant to AI crawlers and answer engines: extractability, E-E-A-T hints, and known AI bot access patterns. Actionable warnings with expandable detail cards. 11. 🗺️ Sitemap Discovery & Health (New) Automatically discovers all sitemaps from robots.txt and fallback paths. Validates XML integrity, checks HTTP status per sitemap, and reports total URLs per locale. Unique: detects duplicate <loc> entries within a single sitemap (intra-file) and across multiple locale sitemaps (cross-file) — with a full drill-down detail pane and CSV export. No other free browser extension does this. 12. 🔍 Sitemap URL Tester (New) Inspect and batch-crawl any sitemap XML with live progress. Checks HTTP status for every URL, captures full redirect chains, and exports results as CSV or JSON. Rate-limit aware: automatic 403/429 backoff with retry queue and tiered pacing for large enterprise sitemaps — won't get blocked by WAFs. Pause and stop at any time. 👥 Who is this for? SEO specialists — Catch canonical bugs, hreflang gaps, robots conflicts, and schema errors on staging or production. Web developers — Validate releases: metadata, headings, structured data, and link health in one pass. QA & test engineers — Find broken links and image issues visually, without digging through DevTools. Content editors — Final pre-publish scan for links, alt text, social cards, and SERP presentation. 🔒 Privacy & Safety Guarantee This extension is built with your privacy in mind: No Telemetry / No Tracking: We do not monitor your browsing behavior or collect usage metrics. No Database Logging: Audit results exist only in the temporary panel window memory and disappear when closed. Local Operation: Direct browser-to-server requests are used for HTTP verification, with zero intermediary proxy servers. Privacy Policy - https://gist.github.com/mbatra5/ae695d34a406fffa6f03f2a6558a6349 --- v1.3.2 Update: • Fixed status 0 errors on cross-origin hreflang checks. • Fixed status badge layout (prevented badge stretching) and enabled URL wrapping in the results tables. • Footer version 1.3.2