How to Detect What Technologies a Website Uses

Wondering what your competitor’s website is built on? Want to know what CMS a client uses before an audit? Or perhaps you’re looking for technological inspiration? In this article, I’ll show you how to detect the technology stack of any website.

Why Detect Technologies?

Knowledge of the technology stack is useful in many situations:

• Competitor analysis - what powers their success
• Before an audit - tailoring recommendations to the platform
• Client prospecting - finding sites on specific CMS
• Inspiration - what industry leaders use
• Security - detecting outdated versions

Popular Tools (and Their Limitations)

BuiltWith

Extensive technology database, but:

• Requires account creation
• Full data is paid
• Slow web interface

Wappalyzer

Popular browser extension:

• Good detection, but limited
• Separate tool from SEO audit
• Doesn’t show context (versions, conflicts)

DevTools

You can manually search the page source, but:

• Time-consuming
• Requires knowing what to look for
• Easy to miss things

UPER SEO Auditor - Technology Detection

The UPER SEO Auditor extension automatically analyzes a website’s technology stack in the Stack tab.

Categories of Detected Technologies

Category	Examples
CMS	WordPress, Drupal, Joomla, Shopify, Wix
JS Frameworks	React, Vue, Angular, Svelte, Next.js, Nuxt
Libraries	jQuery, Lodash, Moment.js, Axios
CSS Frameworks	Tailwind, Bootstrap, Bulma, Foundation
Analytics	GA4, GTM, Hotjar, Clarity, Plausible
Advertising	Google Ads, Facebook Pixel, LinkedIn
CDN	Cloudflare, Fastly, CloudFront, Akamai
Hosting	Netlify, Vercel, AWS, GCP
E-commerce	WooCommerce, Magento, PrestaShop
Chat/Support	Intercom, Zendesk, Tawk.to, Crisp

How Does It Work?

The extension analyzes:

1. HTTP headers - X-Powered-By, Server, custom headers
2. Meta tags - generator, viewport patterns
3. Scripts - paths, global variable names
4. Styles - CSS classes, comments
5. Cookies - platform-specific names
6. DOM - attributes, framework-specific structures

CMS Detection

WordPress

The extension detects WordPress through:

<!-- Meta generator -->
<meta name="generator" content="WordPress 6.4.2">

<!-- Paths -->
/wp-content/themes/theme-name/
/wp-includes/js/jquery/

<!-- REST API -->
/wp-json/wp/v2/

<!-- Comments -->
<!-- This site is powered by WordPress -->

Additional information:

• WordPress version
• Active theme
• Detected plugins (Yoast, WooCommerce, Elementor)

Shopify

<!-- CDN -->
cdn.shopify.com/s/files/

<!-- Cookies -->
_shopify_s, _shopify_y

<!-- JavaScript -->
window.Shopify

Other CMS Platforms

CMS	Signals
Drupal	/sites/default/files/, Drupal.settings
Joomla	/media/jui/, Joomla.optionsStorage
Wix	static.wixstatic.com, wix-code-sdk
Squarespace	static.squarespace.com
Webflow	webflow.com/api/, .w- classes
Ghost	ghost.io, ghost- paths

JavaScript Framework Detection

React

// Global object
window.__REACT_DEVTOOLS_GLOBAL_HOOK__

// DOM attributes
data-reactroot
data-reactid

// Bundler chunks
/static/js/main.*.chunk.js

Vue.js

// Global object
window.__VUE__
window.__VUE_DEVTOOLS_GLOBAL_HOOK__

// Attributes
data-v-*
v-cloak

Next.js

<!-- Meta -->
<script id="__NEXT_DATA__">

<!-- Paths -->
/_next/static/
/_next/image

Angular

// Attributes
ng-version
_nghost-*
_ngcontent-*

// Global
window.ng

Svelte / SvelteKit

<!-- Classes -->
svelte-*
class="s-*"

<!-- Hydration -->
data-svelte-h

Analytics Tools Detection

Google Analytics 4

// Script
gtag('config', 'G-XXXXXXX')

// Global object
window.dataLayer
window.gtag

// Request
google-analytics.com/g/collect

Displayed information:

• Measurement ID (G-XXXXXX)
• Enhanced Measurement enabled
• Debug mode

Google Tag Manager

// Script
googletagmanager.com/gtm.js?id=GTM-XXXXX

// Container
window.google_tag_manager

Displayed information:

• Container ID (GTM-XXXXX)
• Environment (live/preview)

Other Trackers

Tool	Detection
Hotjar	static.hotjar.com, hj()
Microsoft Clarity	clarity.ms, window.clarity
Plausible	plausible.io/js/
Fathom	cdn.usefathom.com
Matomo	matomo.js, _paq

Library Detection

jQuery

window.jQuery
window.$

// Version
jQuery.fn.jquery  // "3.7.1"

Lodash / Underscore

window._
window._.VERSION  // "4.17.21"

Other Popular Libraries

Library	Signal
Axios	window.axios
Moment.js	window.moment
Day.js	window.dayjs
GSAP	window.gsap
Three.js	window.THREE
D3.js	window.d3

CSS Frameworks

Tailwind CSS

<!-- Characteristic classes -->
class="flex items-center justify-between"
class="bg-blue-500 hover:bg-blue-700"
class="px-4 py-2 rounded-lg"

Bootstrap

<!-- Classes -->
class="container"
class="row col-md-6"
class="btn btn-primary"

<!-- CDN -->
cdn.jsdelivr.net/npm/bootstrap

Bulma

class="columns is-multiline"
class="button is-primary"

Practical Applications

1. Before an SEO Audit

Knowing a site uses WordPress + Yoast:

• Check Yoast configuration
• Look for plugin conflicts
• Apply WP-specific recommendations

2. Competitor Analysis

Competitor outranking you? Check:

• What CMS they use
• Better analytics tools
• Performance solutions (CDN, lazy loading)

3. Detecting Outdated Technologies

Stack Detection can find:

• Old jQuery versions (security risk)
• Outdated frameworks
• Deprecated libraries

4. Estimating Migration Costs

Client wants a redesign? Knowing the site is:

• WordPress + WooCommerce + 20 plugins

…you can better estimate the scope of work.

Comparison with BuiltWith

Feature	BuiltWith	UPER SEO Auditor
CMS Detection	✅	✅
JS Frameworks	✅	✅
Versions	Paid	✅
SEO Integration	❌	✅
Offline	❌	✅
Price	$295+/mo	Free

Data Export

Detection results are included in export:

• PDF - Technology Stack section with icons
• JSON - full structure for further analysis

Detection Limitations

Some technologies are hard to detect:

• Server-side frameworks - PHP, Python, Ruby (hidden behind CDN)
• Masked stacks - intentional technology hiding
• Micro frontends - mixed frameworks
• Edge rendering - Cloudflare Workers, Deno Deploy

Summary

Technology detection in UPER SEO Auditor allows you to:

• Quickly identify stack - CMS, frameworks, libraries
• Identify tools - analytics, ads, chat
• Detect versions - security audit
• Integrate with SEO - everything in one panel

Instead of jumping between BuiltWith, Wappalyzer, and DevTools - you have everything in one place.

Try UPER SEO Auditor and check the technology stack of any website.

Sources

1. Wappalyzer - Technology Lookup https://www.wappalyzer.com/

2. BuiltWith - Web Technology Profiler https://builtwith.com/

3. Chrome DevTools - Network Panel https://developer.chrome.com/docs/devtools/network/

4. HTTP Archive - Web Almanac https://almanac.httparchive.org/