Alternatives to the popular website-technology detectors
Wappalyzer, BuiltWith, WhatRuns and the rest all solve the same surface-level question — what is this site built with? — but with very different trade-offs on depth, privacy, pricing and versioning. Below is a short, fair write-up of each, with a focused view on where Sourcemap Explorer fits in.
Wappalyzer
The most-referenced name in website-technology detection — now a paid SaaS with a free browser extension, after its open-source repository was archived in 2023.
BuiltWith
Market-research-oriented technology lookup — strong on technographic reports and lead lists, weaker on per-developer page detail.
WhatRuns
Simple, free-first Chrome extension — lighter than Wappalyzer with a cleaner UI, but with the same detection blind spots and a backend-call-per-lookup architecture.
SimilarTech
Technographics-and-leads platform from the makers of SimilarWeb — sales data dressed as a technology detector.
W3Techs
Aggregate technology-usage statistics across the top N million websites — the go-to source when you need 'what percentage of the web uses X'.
Netcraft
Security-and-research oriented site-technology lookup with a long heritage — strong on hosting, SSL and server-side history, thin on frontend stack.
NerdyData
Source-code-level search across the web — useful for 'who uses this exact code snippet', not for structured per-site technology detection.
Head-to-head comparisons
Where we fit
Sourcemap Explorer is a free, local-first browser extension for per-page research.
We don't compete with BuiltWith's technographic lead lists or Wappalyzer's bulk API. We compete on depth-per-page: exact library versions pulled from sourcemap-embedded package.json files, WordPress plugin enumeration by slug, npm-validated ad-hoc package detection, and third-party tracker isolation so GTM internals never pollute your stack.