Weblyzer - Web Analyzer

Detect the front-end, back-end, CDN, hosting and API technologies behind any website - all locally in your browser.

Weblyzer tells you exactly what a website is built with - and, unlike most detectors, how its back-end, hosting, security and performance hold up - entirely in your browser. No backend server, no account, no tracking. Click the toolbar icon on any site and Weblyzer identifies its stack instantly, grouped into clear categories with a real vendor logo, detected version and confidence level for each technology. A number badge on the icon shows the count before you even open the popup. WHAT IT DETECTS Weblyzer recognises 630+ technologies across over 20 categories: front-end frameworks, UI and CSS libraries, back-end languages, web servers, cloud platforms, CDNs and API gateways, cloud storage, CMS and e-commerce platforms, analytics and marketing tools, authentication and identity providers, and payment processors. Each result shows its category, the detected version where available, and how confident the detection is - so you understand a site's architecture at a glance instead of guessing. SITE HEALTH, SCORED LOCALLY - Security grade (A+ to F) - audits common response-security headers and flags version or information leaks - Performance grade (A to F) - based on the page's real Core Web Vitals - Vulnerability hints - matches detected library versions against publicly known CVEs DIG INTO THE BACK-END - API map - the real REST, GraphQL, WebSocket and SSE calls a page makes, with GraphQL operation names and optional schema introspection - Hosting & network - server IP, ASN, ISP, location and reverse DNS, plus the TLS version and server certificate (Firefox) - DNS & email recon - reads public DNS records to reveal the email host, DNS host and certificate authority - Well-known recon - reads public files such as robots.txt and security.txt to reveal the identity provider - JWT inspector - decodes auth tokens from the page's own storage locally (header and claims only; never verified or sent anywhere) - SEO & meta inspector - title, description, canonical, Open Graph and Twitter Card tags, hreflang, and Schema.org (JSON-LD) structured data - Cookie & request inspector - every cookie with its Secure / HttpOnly / SameSite flags, plus a breakdown of all network requests by type and host - Third-party and tracker map - every external domain the page talks to, grouped by category WORK THE WAY YOU WANT - Compact popup for a fast glance; full-page report for the detail - Export any report as an image, text, Markdown or JSON - History of the sites you have analyzed - Available for Chrome, Firefox, and Firefox for Android PRIVACY FIRST 100% local by default. Weblyzer has no backend and sends nothing to the developer. Every network request is opt-in and reaches only the site you are on or a clearly labelled public IP/DNS service. See the privacy policy for full details.