Tech Stack & SEO Inspector: Technology Detector, CMS & SEO Checker

Click the icon on any website to see what it's built with and how its on-page SEO scores: a technology detector, CMS detector and SEO checker in one popup. What CMS is this site using? Is it Shopify, WordPress or Webflow? Which JavaScript framework, analytics, tag manager or CDN? And how does its on-page SEO hold up? Answer all these questions and more. Everything runs on your computer: no account, no tracking, and nothing about the pages you inspect leaves your browser. TECH STACK • About 3,500 technologies: CMS, ecommerce platforms, JavaScript frameworks and libraries, analytics, tag managers, CDNs, hosting, payments, marketing tools and more • Grouped by category, with versions where the page reveals them and a confidence score • Open any row to see the evidence: the script, meta tag, header, element, cookie name or JavaScript variable that matched • Sees what server-side scanners miss: JavaScript variables, elements added after load, and scripts that tag managers load later SEO SCORE (0-100) • Title and meta description length • Canonical URL, noindex and nofollow (meta tag and X-Robots-Tag header) • H1 count and heading order • Image alt text coverage, image-only links, missing image dimensions • Open Graph and Twitter card tags • Structured data (JSON-LD types, and blocks that don't parse) • hreflang, viewport, lang attribute, word count • Mixed content, internal, external and nofollow link counts Each check says what it found and why it matters. Errors cost 20 points, warnings 8, notices 2. FREE: unlimited tech stack and SEO score for any page. PRO ($4.99 a month or $39 a year): • History for every site you inspect, kept on your device, with "what changed since your last visit": technologies added or removed, version changes, SEO score up or down, issues fixed or new • Export to CSV, JSON or Markdown, or copy the report to the clipboard • Compare two sites side by side PRIVATE BY DESIGN • Reads a page only when you click the icon (activeTab), never in the background • No access to all websites, no analytics, no remote code • Pro history stays in your browser; payments and license keys are handled by Polar Good for web developers sizing up a project, SEO consultants doing quick audits, agencies and sales teams researching prospects, and anyone curious how a site is made. Technology fingerprints are based on the Wappalyzer project's last MIT-licensed release (2023) plus our own additions. Not affiliated with Wappalyzer or BuiltWith. Technology fingerprints are based on the Wappalyzer project's last MIT-licensed release (2023) plus our own additions. Not affiliated with Wappalyzer or BuiltWith. Docs: https://apps.michael-ang-costa.workers.dev/tech-stack-seo-inspector/