How do I find out what JavaScript framework a website uses?

Paste the URL into a framework detector, or manually view the page source and look for script filenames like react.production.min.js or vue.min.js, or root container IDs like __next (Next.js) or __nuxt (Nuxt).

Can I tell the difference between React and Next.js on a site?

Yes. Next.js sites show a distinctive __next root container and load assets from a _next/static/ path, which is a more specific signal than the generic React signature and is reported when present.

Does framework detection work on server-rendered sites with minimal JavaScript?

Detection relies on framework-specific signatures appearing in the HTML or asset paths. A site using a framework only for server-side rendering with minimal client-side JavaScript may still show build artifact signatures (like Next.js's _next/static path) even with limited visible interactivity.

What does it mean if no framework is detected?

The site is likely built with traditional server-rendered HTML and minimal or no JavaScript framework, or uses a framework not yet covered by the detection signature library.

Can I detect Svelte even though it compiles away at build time?

Yes. Svelte's compiler output retains a distinctive class naming pattern (svelte-[hash]) in the generated CSS, which remains a reliable detection signal even though the framework itself isn't present as a runtime library.

Is Gatsby considered React or its own separate category?

Gatsby is built on React internally but produces its own distinctive signature (a ___gatsby root container and specific build artifacts), so it's detected and reported as Gatsby specifically rather than generic React.

Why does framework choice matter for understanding a website?

Framework choice indicates the development approach and performance profile — a statically generated site (Astro, Gatsby) typically loads faster than a fully client-rendered single-page application, and the choice often reflects the team's technical priorities.

Can a website use more than one framework at once?

It's uncommon but possible during a migration period, or if different sections of a site (a blog versus an app) were built separately. Detection would identify whichever framework signature is present on the specific page checked.

Does framework detection require loading the full page in a browser?

No — detection reads the static HTML response and script source attributes, which doesn't require executing JavaScript the way a full browser rendering would.

Is Angular detectable the same way as React and Vue?

Yes, through its own distinctive signatures — Angular applications typically show ng- prefixed attributes and a characteristic root application tag, detected the same way other framework signatures are matched.

Why would I want to know a competitor's framework choice?

It indicates their development approach and team capability — a custom React or Next.js build generally signals more engineering investment than a templated CMS, useful context when evaluating a competitor's technical sophistication.

How current does a framework detection signature library need to be?

Major frameworks change their core build output infrequently, so signatures for established frameworks remain stable for long periods, though newer or fast-evolving frameworks may require more frequent signature updates.

Identify Website Framework

How to detect the JavaScript framework or static site generator behind any website, and what each signature looks like

Modern websites are frequently built on a JavaScript framework rather than a traditional server-rendered CMS, and each framework leaves its own distinctive signature in script sources, build artifacts, and sometimes meta tags. This page covers how framework detection works and what signals distinguish the major options.

Base Frameworks vs. Meta-Frameworks

React and Vue are base frameworks — libraries for building user interfaces, without an opinionated structure for routing, server rendering, or build configuration. Next.js and Nuxt are meta-frameworks built on top of them, adding routing, server-side rendering, and a standardized project structure. A site can use React directly or use Next.js (which uses React internally) — detection distinguishes between these because the meta-framework introduces its own additional, more specific signature.

Next.js sites show a distinctive __next root container in their HTML and load assets from a _next/static/ path. Nuxt sites show a __nuxt root container and load assets from _nuxt/. When these meta-framework signatures are present, they're reported instead of just the underlying base framework, since they're more informative about the site's actual technical setup.

Static Site Generators and Newer Frameworks

Astro, Gatsby, and similar static site generators produce their own distinctive output even though some are built on React or other base frameworks internally. Astro sites are identifiable by astro-island custom HTML elements used for selective hydration. Gatsby sites show distinctive ___gatsby root containers and a characteristic webpack-generated asset structure. Svelte compiles away the framework itself at build time, but produces a distinctive class naming convention (svelte-[hash]) in its compiled CSS output that remains detectable.

Detecting these accurately matters because each represents a meaningfully different technical and performance profile — a statically generated Astro or Gatsby site behaves very differently in terms of load performance and hosting requirements than a fully client-rendered React single-page application, even though both might appear similar at a glance.

Framework Detection Signals

Meta-frameworks are detected via their own more specific signature, which takes precedence over the underlying base framework when both are present.

Framework	Primary Detection Signal	Category
React (standalone)	react.production.min.js script source	Base framework
Vue (standalone)	vue.min.js script source, v- directive attributes	Base framework
Next.js	__next root container, _next/static/ asset path	Meta-framework (React-based)
Nuxt	__nuxt root container, _nuxt/ asset path	Meta-framework (Vue-based)
Astro	astro-island custom elements	Static site generator
Gatsby	___gatsby root container	Static site generator (React-based)
Svelte	svelte-[hash] compiled class naming	Compiled framework

Identify Website Framework

Base Frameworks vs. Meta-Frameworks

Static Site Generators and Newer Frameworks

Framework Detection Signals

Sources & Further Reading

Frequently Asked Questions

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