Tech Stack Guides
149 articles
How to Tell If a Website Uses Trustpilot
Trustpilot is the leading independent reviews platform. Detect it via TrustBox widgets from widget.trustpilot.com, the trustpilot-widget div with data-businessunit-id, and invitejs.trustpilot.com.
How to Tell If a Website Uses GSAP
GSAP (GreenSock) is the leading web-animation library. Detect it via the window.gsap global, the gsap.min.js script, ScrollTrigger and legacy TweenMax/TweenLite references.
How to Tell If a Website Uses Material UI (MUI)
Material UI (MUI) is the most popular React component library. Detect it via Mui- prefixed class names, Emotion's css-<hash> classes and the data-emotion style tags in the DOM.
How to Tell If a Website Uses Sentry
Sentry is the leading error- and performance-monitoring platform for web apps. Detect it via the @sentry/browser SDK, the window.Sentry object, the DSN in Sentry.init() and ingest.sentry.io envelope requests.
How to Tell If a Website Uses Yoast SEO
Yoast SEO is the most popular WordPress SEO plugin. Detect it via its HTML comments, the /wp-content/plugins/wordpress-seo/ assets and the Yoast schema graph it outputs.
How to Tell if a Website Uses jQuery (and Which Version)
jQuery is easy to detect: a jquery.min.js file, the window.jQuery and $ objects in the Console, and jQuery.fn.jquery prints the exact version. Here is how.
How to Tell if a Website Uses Hotjar or Another Heatmap Tool
Hotjar, Clarity, FullStory and Crazy Egg leave clear fingerprints — script domains, cookies and global objects. Here is how to detect a site's heatmap tool.
How to Tell if a Website Uses Akamai, Fastly, or CloudFront
Each major CDN leaves distinct header fingerprints — Fastly's x-served-by, Akamai's ghost markers, CloudFront's x-amz-cf-pop. Here is how to tell them apart.
How to Tell if a Website Is Built with WooCommerce
WooCommerce is WordPress plus Woo: woocommerce-* body classes, a /wp-content/plugins/woocommerce/ path and wc-* cart scripts. Here is how to detect it.
How to Tell if a Website Uses Progressive Web App (PWA) Features
A web app manifest, a registered service worker, installability and a theme-color tag are the PWA signals. Here is how to detect them in Chrome DevTools.
How to Tell if a Website Is Built with Gatsby
Gatsby leaves clear client-side tells: /page-data/ JSON requests, a ___gatsby div and app-*.js bundles. Here is how to detect this React static-site generator.
How to Tell if a Website Uses Bootstrap (and Which Version)
Bootstrap leaves clear fingerprints: container/row/col-md-6 classes, bootstrap.min.css and data-bs-* attributes. Here is how to detect it and pin the version.
How to Tell if a Website Is Built with Magento (Adobe Commerce)
Magento leaves clear fingerprints: /static/version*/ and /media/ paths, X-Magento cache headers and Magento_* RequireJS modules. Here is how to detect it.
How to Tell if a Website Is Hosted on AWS
AWS leaves fingerprints in headers, cookies, DNS and IP ranges — x-amz-* markers, CloudFront, ELB cookies and amazonaws.com DNS. Here is how to read them.
How to Tell if a Website Uses Google reCAPTCHA
Google reCAPTCHA leaves signals: a recaptcha/api.js script, a grecaptcha global and a g-recaptcha data-sitekey. Here is how to detect it and tell v2 from v3.
How to Tell if a Website Uses the Meta (Facebook) Pixel
The Meta Pixel leaves clear signals: an fbevents.js script, an fbq('init') call, a _fbp cookie and tr beacons to facebook.com. Here is how to detect it.
How to Tell if a Website Is Built with Ruby on Rails
Rails runs server-side, but it leaves tells: a _session cookie, a csrf-token meta tag, fingerprinted /assets/ files and an X-Request-Id header. Here is how.
How to Tell if a Website Is Built with Django
Django runs server-side in Python, but it leaves tells: csrftoken and sessionid cookies, /static/ paths and its admin login page. Here is how to spot them.
How to Tell if a Website Is Hosted on Vercel or Netlify
Vercel and Netlify leave clear header fingerprints — x-vercel-id and x-nf-request-id among them. Here is how to tell which platform hosts a site, fast.
How to Tell if a Website Is Built with Svelte or SvelteKit
Svelte and SvelteKit leave clear fingerprints: svelte-<hash> scoped classes, data-sveltekit-* attributes and /_app/ chunks. Here is how to detect them fast.
How to Tell if a Website Uses Google Analytics 4
Google Analytics 4 leaves clear signals: a gtag.js script, a G-XXXXXXX measurement ID, /g/collect requests and _ga cookies. Here is how to spot it fast.
How to Tell if a Website Uses a Cookie Consent Tool (CMP)
OneTrust, Cookiebot, Osano and Usercentrics leave fingerprints: consent banners, scripts and cookies like OptanonConsent. Here is how to detect a site's CMP.
How to Tell if a Website Uses Tailwind CSS
Tailwind CSS leaves a tell-tale fingerprint: utility-class soup like flex pt-4 text-sm md:grid-cols-3 and arbitrary values like w-[327px]. Here is how to detect it.
How to Find Out What Server Software a Website Runs (Nginx, Apache, LiteSpeed)
The Server response header usually names the web server — nginx, Apache, LiteSpeed, IIS or Caddy. Here is how to read it, and why CDNs and proxies often hide it.