Tech Stack & SEO Inspector

See the technologies behind any website and get an instant on-page SEO score. Private: runs on your device.

Click the icon on any website to see what it's built with and how its on-page SEO scores. 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 ($3.99 a month or $29 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. Docs: https://apps.michael-ang-costa.workers.dev/tech-stack-seo-inspector/