April 9, 2026Updated April 10, 20267 min readby Vladimir Kamenev

Free Website Technology Checker — Detect CMS, Frameworks, Analytics & More

The one-line answer

Our free website technology checker tells you exactly what any website is built on — CMS, JavaScript frameworks, analytics tools, CDN, hosting, payment processors, and 50+ other technologies — in about 15 seconds, with no signup required.

Why check what a site is built on

Knowing a site's tech stack isn't just trivia — it's leverage. Here's why thousands of marketers, developers, and founders run a free website technology checker on sites every day:

Competitive research. If a competitor is crushing it on organic traffic, the first question is always: what are they running under the hood? Are they on Next.js with edge caching, or a bloated WordPress setup with 40 plugins? The stack tells a story.

Tech due diligence. Evaluating an acquisition target, agency, or vendor? A quick CMS detector run tells you whether the site is on modern infrastructure or a rotting stack that will cost six figures to replace.

Lead generation. Sell SEO services? Filter prospects by CMS — WordPress sites are your ideal customer. Sell Shopify apps? Find Shopify stores. A free website technology checker turns any URL into a qualified lead or a disqualified one.

Sales enablement. If your product integrates with HubSpot or Intercom, you want to know which prospects already run those tools before the first call.

Migration planning. Moving off Wix to Webflow? Off WordPress to Astro? Audit where you are today before you plan where you're going.

Pure curiosity. Sometimes you just want to know how a beautiful site was built so you can steal the recipe.

What our free website technology checker detects

We scan across 50+ signatures in 10 categories. Here's the full breakdown:

Content management systems (9): WordPress, Shopify, Wix, Squarespace, Webflow, Ghost, Drupal, Joomla, Astro. This is where most CMS detector queries start — and our tool catches the obvious signals (wp-content paths, Shopify CDN domains, Wix HTML comments) as well as the subtle ones. JavaScript frameworks (8): React, Next.js, Vue.js, Nuxt, Angular, Svelte, jQuery, Preact. We detect framework-specific build artifacts, window globals, and script bundle patterns so you know whether a site is server-rendered, SPA, or hybrid. Analytics and tracking (10): Google Analytics 4, Google Tag Manager, Meta Pixel, Hotjar, Microsoft Clarity, Plausible, Fathom, Matomo, Amplitude, Mixpanel. This is gold for growth teams — see exactly which tools your competitors rely on for attribution and behavioral data. CDN (7): Cloudflare, Fastly, AWS CloudFront, Vercel, Netlify, Akamai, Bunny CDN. Detected via response headers, edge domains, and known IP ranges. Hosting (5): AWS, Google Cloud, Heroku, DigitalOcean, Firebase. Useful for infrastructure benchmarking and cost modeling. Payment processors (3): Stripe, PayPal, Square. Critical for e-commerce competitor analysis. Marketing and support (5): HubSpot, Mailchimp, Intercom, Drift, Zendesk. Know who your prospect is already sending emails with and chatting with customers through. Chat widgets (3): Crisp, Tawk.to, LiveChat. Fonts (3): Google Fonts, Adobe Fonts, Font Awesome. Handy for design audits and performance work (Google Fonts alone can blow your LCP budget). Security and bot protection (3): reCAPTCHA, hCaptcha, Cloudflare Turnstile.

How the free website technology checker works

Under the hood, our tool is pattern-based — no magic, just careful engineering. When you submit a URL, we fetch the page server-side and inspect four sources of signals:

HTML body — we look for known comments, class names, data attributes, and inline markers (for example, wp-content for WordPress, __NEXT_DATA__ for Next.js, .shopify URLs for Shopify).

HTTP response headers — server, x-powered-by, cf-ray, x-vercel-id, and similar reveal hosting, CDN, and framework choices that never appear in HTML.

Script and asset URLs — the domains your site loads JavaScript from are a fingerprint. gtag/js means GA4. static.hotjar.com means Hotjar. js.stripe.com means Stripe.

Meta tags — generator tags and OpenGraph metadata often announce the CMS directly.

Each signature is a carefully tuned rule with a confidence score. If a site loads react.production.min.js AND has a __REACT_DEVTOOLS_GLOBAL_HOOK__ reference AND its HTML contains data-reactroot, confidence is very high. One signal alone is flagged as probable rather than confirmed.

How to use it (3 steps)

Go to the free website technology checker.

Paste any URL — your own site, a competitor, a prospect, whatever you're curious about.
Wait about 15 seconds. You'll get a categorized report showing every technology we detected with confidence scores and documentation links.

That's it. No signup. No credit card. No email wall.

How we compare to Wappalyzer and BuiltWith

The two tools every marketer has heard of are Wappalyzer and BuiltWith. Here's the honest comparison:

Wappalyzer started life as a beloved open-source browser extension that detected ~3,000 technologies inline while you browsed. It was acquired in 2021 and aggressively commercialized — the free browser extension still exists, but the open API and bulk lookups are now paywalled behind enterprise pricing. Great if you want a browser tab-by-tab experience, frustrating if you want to check sites at scale or without installing anything. BuiltWith is the industry heavyweight, with 111,000+ technology signatures and the deepest historical database. It's also the most expensive option in the category — pricing starts at around $295/month, with real power locked behind the $495 and $995/month plans. It's overkill (and over budget) for anyone who just wants to know what CMS a single site uses. Our free website technology checker sits in the gap that matters for most people: free, web-based, no signup, no install, no credit card. We don't try to match BuiltWith's 111,000-signature database — we cover the 50+ technologies that actually matter for competitive research, lead gen, and tech due diligence. You paste a URL, you get an answer, you move on. And the results are also available programmatically through our free API, so you can build your own workflows on top of it.

If you need a historical database of every CMS a Fortune 500 company ever used, pay for BuiltWith. If you need a free website technology checker that just works, use ours.

Real-world use cases

Competitive research: "What stack is my competitor running?" Paste the URL, see the CMS, framework, analytics, CDN, and chat tools in one view. No more guessing.

Lead generation for agencies: Build a list of sites running outdated WordPress or abandoned Wix themes, then pitch SEO or redesign services. Our CMS detector is the fastest way to qualify in or out.

Sales enablement for SaaS: If your product has a Shopify, HubSpot, or Stripe integration, use the checker to match prospects to sites already using the companion tool. Warm intros sell better than cold pitches.

Pre-call prospect audits: Before a sales call, run the prospect's URL and walk into the meeting knowing their stack, their analytics tools, and their likely pain points. It takes 30 seconds and makes you look like you did homework.

Vendor / agency evaluation: Thinking about hiring an agency? Run the free website technology checker on their own site and the sites of their client case studies. If the agency can't ship modern tech for itself, it won't ship it for you.

Try the free website technology checker

Stop guessing. Paste any URL into our free website technology checker and find out exactly what it's built on — CMS, frameworks, analytics, CDN, payments, everything. No signup, no paywall, no upsell.

FAQ

Is the free website technology checker actually free, or is there a catch? Actually free. No signup, no credit card, no email wall. We built it because the existing options (Wappalyzer's paid API, BuiltWith's $295/month floor) are overkill for 95% of real-world use cases. You can run it on as many URLs as you want. How is this different from Wappalyzer and BuiltWith? Wappalyzer is primarily a browser extension and its bulk/API features have been paywalled since acquisition. BuiltWith is powerful but expensive ($295/month+). Our free website technology checker is web-based, requires no install, detects the 50+ most common technologies, and is free. We're optimized for people who want a fast answer, not a 111,000-signature database. Can it detect every technology on a site? Almost — but not quite. We cover 50+ high-value signatures across CMS, JS frameworks, analytics, CDN, hosting, payments, marketing, chat, fonts, and security. If a site uses something extremely niche, we might miss it. For the tools that actually drive business decisions (WordPress, Shopify, React, GA4, Stripe, Cloudflare, HubSpot, etc.), our detection is reliable. Is there an API I can use to build my own tools on top of it? Yes. The same endpoint that powers our web CMS detector is available as a free JSON API. Hit it with a URL, get a structured response back. Perfect for building internal prospecting tools, enriching CRM records, or running audits at scale. Contact us and we'll point you at the docs.