Introduction
Wappalyzer is a technology profiler that identifies the software running behind any website. It detects content management systems, JavaScript frameworks, analytics tools, server software, and hundreds of other technologies by analyzing HTTP headers, HTML source, JavaScript variables, and other fingerprints.
What Wappalyzer Does
- Detects CMS platforms like WordPress, Drupal, Shopify, and Joomla
- Identifies JavaScript frameworks and libraries such as React, Vue, Angular, and jQuery
- Reveals server software, CDN providers, and hosting platforms
- Recognizes analytics tools, tag managers, and marketing pixels
- Categorizes detected technologies into over 100 categories
Architecture Overview
Wappalyzer uses a pattern-matching engine driven by a JSON-based fingerprint database. Each technology entry defines detection rules based on HTTP response headers, HTML content patterns, script sources, meta tags, cookies, and JavaScript global variables. The browser extension runs these rules against the current page and reports matches. The fingerprint database is community-maintained and receives regular updates.
Self-Hosting & Configuration
- Install the browser extension from Chrome Web Store or Firefox Add-ons
- Use the npm package for server-side detection in Node.js applications
- Integrate via the Wappalyzer API for bulk website technology lookups
- Contribute new technology fingerprints by editing the technologies JSON files
- Self-host the detection engine using the open-source core library
Key Features
- Detects over 1,700 web technologies across 100+ categories
- Community-maintained fingerprint database with frequent updates
- Available as a browser extension, npm library, and REST API
- Supports detection via headers, HTML patterns, cookies, DNS, and JavaScript globals
- Open-source core with a permissive license
Comparison with Similar Tools
- BuiltWith — commercial SaaS with a larger database; Wappalyzer is open source and free for personal use
- WhatRuns — browser extension with similar detection; Wappalyzer has a larger open-source community
- Netcraft — focuses on security and server info; Wappalyzer covers the full application stack
- Shodan — scans internet-facing infrastructure; Wappalyzer analyzes individual website tech stacks
FAQ
Q: Is Wappalyzer free? A: The browser extension and open-source library are free. The commercial API and bulk lookup service require a paid plan.
Q: How does Wappalyzer detect technologies? A: It matches patterns in HTTP headers, HTML source, JavaScript globals, cookies, and DNS records against a curated database of technology fingerprints.
Q: Can I add detection for a new technology? A: Yes. The fingerprint database is open source and accepts community contributions via pull requests on GitHub.
Q: Does Wappalyzer work on single-page applications? A: Yes. It analyzes JavaScript globals and script sources, which are present in SPAs even when the HTML is minimal.