StackSight

Instantly discover the technology behind any website. Detect CMS, frameworks, analytics, CDN, cloud providers, and security headers.

🔍 STACKSIGHT — INSTANTLY DISCOVER ANY WEBSITE'S TECH STACK One click. One second. Zero data sent anywhere. StackSight is a free, open-source Chrome Extension that reveals the technology stack powering any website you visit — the content management system, frontend framework, analytics tools, hosting infrastructure, and security posture — without sending a single byte of your data to any server. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔍 WHAT IT DETECTS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🗂 CONTENT MANAGEMENT SYSTEM StackSight identifies which CMS is powering a site — whether it's a popular blogging platform, an e-commerce solution, an open-source enterprise system, or a hosted website builder. It detects over 9 platforms using DOM signals, JavaScript globals, response headers, and generator meta tags. ⚙️ FRONTEND FRAMEWORKS & LIBRARIES The extension identifies the JavaScript framework or UI library used to build the front end — including major React-based, Vue-based, and Angular-based ecosystems, as well as newer compile-time frameworks and utility-first approaches. Common animation libraries and CSS frameworks are also detected. 📈 ANALYTICS & TRACKING TOOLS StackSight reveals which analytics and tracking tools are loaded on a page — including tag managers, session-recording tools, heatmap services, A/B testing platforms, customer messaging tools, and error monitoring services. It detects 18+ tools and uses the count to calculate a privacy score. ☁️ CLOUD & HOSTING INFRASTRUCTURE The extension identifies where a website is hosted — major cloud platforms, modern edge-hosting providers, and traditional PaaS services — using response headers, asset URL patterns, and server signatures. 🌐 CONTENT DELIVERY NETWORK StackSight detects which CDN is serving the site's assets, using HTTP headers such as cache-status identifiers and server signatures, as well as asset URL patterns pointing to CDN domains. 🔒 SECURITY HEADER AUDIT The extension performs a live audit of 7 critical HTTP security headers — Content-Security-Policy, Strict-Transport-Security (HSTS), X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and Cross-Origin-Opener-Policy — and produces a score from 0 to 100 with a letter grade (A+ to F). Missing headers are listed with plain-English remediation advice. ⚡ PERFORMANCE SNAPSHOT StackSight counts the page's scripts, stylesheets, images, web fonts, and third-party resources, and flags counts that exceed recommended thresholds with actionable recommendations. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔒 100% PRIVATE — YOUR DATA NEVER LEAVES YOUR BROWSER ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ StackSight is built with privacy as a first-class feature: • No data collection of any kind • No account or login required • No analytics inside the extension itself • No cookies set by the extension • No cloud storage, no database, no backend server • All processing happens locally in your browser • The only outbound request is a HEAD call to the site you are already visiting, to read its response headers ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📤 EXPORT YOUR ANALYSIS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Download your full analysis as: • JSON — structured and machine-readable, ideal for automation or archiving • TXT — human-readable report suited for client deliverables or documentation Both formats are generated entirely in your browser and downloaded locally. No upload, no server. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🌗 DARK & LIGHT MODE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Beautiful dark UI by default with a one-click toggle to light mode. Your theme preference is saved automatically between sessions. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📖 OPEN SOURCE — MIT LICENSE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ StackSight is 100% open source and MIT licensed. Every line of code is on GitHub. Contributions, bug reports, and feature requests are always welcome. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 👥 WHO IS STACKSIGHT FOR? ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ • Developers who want to understand a site's architecture before joining a project or evaluating a codebase • Technical marketers performing competitive technology research • Agencies and consultants running discovery sessions before onboarding new clients • Security researchers auditing HTTP header configurations • Curious technologists who wonder what any given website is built with ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 💬 SUPPORT ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Found a bug or want a new technology detected? Open an issue on GitHub. StackSight is free forever. No premium version. No subscription. No upsell.