JavaScript Framework Detector — Is It React, Vue, or Angular?

Paste a URL. Instantly see whether the site is built with React, Vue, Angular, Next.js, Svelte, Nuxt, Remix, or another framework. Free, instant, no signup.

Try: vercel.com · vuejs.org · angular.dev · svelte.dev

Frameworks & Libraries This Detector Identifies

DetectZeStack fingerprints front-end frameworks, meta-frameworks, and the build tools behind them.

Reactdata-reactroot, react bundles
Next.js/_next/, __NEXT_DATA__
Vue.jsdata-v-, Vue runtime
Nuxtwindow.__NUXT__, /_nuxt/
Angularng-version, zone.js
Sveltesvelte-* classes, SvelteKit
Remix__remixContext
Gatsby/page-data/, ___gatsby
Ember.jsember-application class
Preactpreact bundle signatures
Alpine.jsx-data attributes
jQuerywindow.jQuery, $.fn
Astroastro-island, _astro/
Vite/@vite/, modulepreload
WebpackwebpackJsonp chunks
+ morevia bundle & global signatures

How It Works

Framework detection reads what the page actually ships — not what it claims — across four signal types.

Asset paths/_next/, /_nuxt/, /@vite/, /page-data/ — meta-frameworks leave a tell-tale build directory.
Global objects & data scriptswindow.React, __NEXT_DATA__, window.__NUXT__, __remixContext.
DOM attributesdata-reactroot, ng-version, data-v-, x-data — runtime markers in the rendered HTML.

Need This in Code? Use the API

Same detection, programmatic — audit a portfolio, qualify dev-tool prospects by stack, or watch a re-platforming.

curl "https://detectzestack.com/analyze?url=vercel.com" \
  | jq '.categories["JavaScript frameworks"]'

# Output:
# ["React","Next.js"]

100 requests/month free — grab an API key. Paid plans from $9/month for 1,000 requests. Full docs: OpenAPI spec.

Frequently Asked Questions

How can I tell what JavaScript framework a website uses?

Paste the URL into the detector above. It inspects script bundles, global variables, build-artifact paths, and DOM attributes to name the framework in a couple of seconds.

Can it tell React from Next.js?

Yes. Next.js exposes a /_next/ path and a __NEXT_DATA__ script, so it's reported separately from a plain React SPA. Nuxt is likewise distinguished from plain Vue, and Remix from plain React.

Is this framework detector free?

Yes — free, no signup. For bulk or programmatic detection, grab a free API key (100 requests/month, no credit card), paid plans from $9/month.

Why does a site show no framework?

Server-rendered sites (plain HTML, Rails, Laravel, WordPress) often ship little front-end framework. Svelte also compiles away much of its runtime, leaving a smaller footprint to fingerprint.

Is this better than a browser extension?

Extensions only read the rendered page in your browser. This detector also inspects server responses and asset paths — and exposes results via API for bulk use. See how to detect a React website.

Detect Frameworks Programmatically

100 free API requests per month. No credit card.

Get Free API Key

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