How do I find out what a website is built with?

The easiest way is to use a free tech stack detector like LaunchBuff's. It fetches the page HTML and HTTP headers and matches known fingerprints — script URLs, CSS class names, header values like X-Powered-By and CF-Ray — to identify frameworks, hosting, analytics, and payment tools. You can also inspect the page source manually or look for tell-tale script URLs.

Is this tech stack detector free?

Yes. The LaunchBuff Tech Stack Detector is completely free with no account required. Paste any URL and get results instantly.

How accurate is tech stack detection?

Detection accuracy depends on whether the technology leaves public signals in the HTML or response headers. Client-side technologies (React, Next.js, Tailwind, analytics scripts) and hosting providers (Cloudflare, Vercel, AWS) are usually detectable with high confidence. Pure server-side technologies with no frontend fingerprint (certain databases, internal APIs) cannot be detected from public signals alone.

Why would I want to know a competitor's tech stack?

Knowing a competitor's tech stack helps you benchmark your own choices, understand their infrastructure costs, spot potential weaknesses, and evaluate whether their tech decisions are a signal of scale or early-stage pragmatism. Founders also use it for stack inspiration — seeing what successful products use to handle payments, auth, and analytics informs their own architecture decisions.

Can this detect if a site uses Next.js, React, or Vercel?

Yes. Next.js leaves distinctive markers: the __NEXT_DATA__ script tag and /_next/ asset paths. React is identified by react-dom script URLs or the window.__REACT_DEVTOOLS__ hook. Vercel is detected via the x-vercel-id and x-vercel-cache response headers. All three are detected with high confidence.

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Tech Stack Detector

Enter any URL and instantly see what the site is built with — frameworks, CSS, hosting, analytics, payments, and more. Detected from public signals, no login required.

What we detect

40+ technologies across 12 categories, detected from public HTML and response headers.

⚡Framework

🎨CSS

☁️Hosting

🗄️Backend

📝CMS

🧩No-Code

🛒E-Commerce

📊Analytics

💳Payments

💬Support

🔐Auth

🤖AI

Technologies detected

A selection of the specific tools and frameworks we identify. The full fingerprint list is broader — these are the most commonly found technologies.

⚡Framework

ReactNext.jsVue.jsNuxtSvelteSvelteKitAstroRemixAngular

🎨CSS

Tailwind CSSBootstrapBulmaChakra UIMantineshadcn/ui

☁️Hosting

VercelCloudflareNetlifyAWSGoogle CloudRailwayFly.ioHeroku

📊Analytics

Google Analytics 4PlausiblePostHogMixpanelAmplitudeHotjarFathom

💳Payments

StripePaddleLemon SqueezyPolar.shPayPalBraintree

🔐Auth

Supabase AuthAuth0ClerkFirebase AuthOkta

📝CMS

ContentfulSanityWordPressGhostStrapiPrismic

💬Support

IntercomCrispZendeskHelpScoutTidioTawk.to

Why founders check competitor stacks

A site's tech choices are a compressed signal about team size, build philosophy, and infrastructure cost. Here's what founders actually look for.

🔭

Benchmark your own stack decisions

When a fast-moving startup is getting traction, founders want to know if they're outbuilding you. Seeing they're on Next.js + Vercel vs. your bare Express server is a useful signal.

💸

Estimate infrastructure costs

Cloudflare + PlanetScale vs. AWS EC2 + RDS tells you a lot about a competitor's burn rate. Tools visible in the stack often hint at team size and spend.

🛠️

Get stack inspiration for your own build

Successful products are the best signal of what actually works at scale. Seeing that three similar products all use the same payment stack removes decision paralysis.

🔍

Spot acquisition due diligence signals

A site still running jQuery in 2025 or missing basic analytics suggests limited engineering investment. Tech debt is visible if you know where to look.

How detection works

①

Fetch the page

We fetch the public HTML from the URL you provide, same as any visitor.

②

Read the signals

HTTP headers (Server, X-Powered-By, CF-Ray) and HTML patterns (script URLs, CSS classes, data attributes) reveal the stack.

③

Group and display

40+ technology fingerprints matched, grouped by category with confidence indicators.

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Frequently asked questions

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