What Is React?
Website BuilderReact is the most widely-used JavaScript library for building user interfaces, developed and maintained by Meta. It introduced a component-based architecture and a virtual DOM for efficient updates. React powers millions of websites and applications, often paired with frameworks like Next.js, Remix, or Gatsby.
Detect React on any website:
Why React Matters
If you're weighing React for a new site, auditing a competitor's stack, or figuring out why a prospect's website looks the way it does, the platform choice drives everything downstream: hosting cost, SEO control, performance ceiling, and migration pain later. We've fingerprinted React on 30 live sites in our database, so the answers here are grounded in real scan data — not marketing copy.
How Websites Using React Work
- Declarative, component-based UI architecture
- Virtual DOM for efficient diffing and DOM updates
- Unidirectional data flow with state and props
- Massive ecosystem of hooks, libraries, and tools
- JSX syntax combining JavaScript and HTML-like markup
- Used both as a single-page app library and with SSR frameworks
Best Practices When Working With React
Based on patterns in our scan dataset and the detection evidence tiers.
- →Start by running a React detection scan on any URL you're evaluating — the 80+ signal engine returns a confidence score plus the exact markers it matched, which beats reading view-source by hand.
- →Cross-check the result against the full detection evidence in /how-scores-work — confidence tiers tell you whether a match is strong (headers + scripts) or circumstantial (a single HTML pattern).
- →Pair this page with the builder gallery (/gallery/react) to see how React sites look in the wild and spot the design patterns that repeat across real deployments.
- →For migration planning, compare React against other builders in the same category — feature parity usually matters more than raw popularity.
How we detect React — see our methodology: AI Influence Score calculation, evidence tiers, and fingerprint signal types.
How Our Detector Identifies React
Our scanner analyzes multiple layers of a website's technical fingerprint to detect React usage.
- react.development.js or react.production.min.js in page scripts
- __REACT_FIBER_TRACING__ or __reactFiber attributes in DOM
- React DevTools hook detection in window object
- Technology stack entry listing React as the framework
- JSX-compiled output patterns in page JavaScript bundles
Websites Built With React
Real sites detected by our scanner
Frequently Asked Questions About React
What is React?+
React is the most widely-used JavaScript library for building user interfaces, developed and maintained by Meta. It introduced a component-based architecture and a virtual DOM for efficient updates. React powers millions of websites and applications, often paired with frameworks like Next.js, Remix, or Gatsby.
Why does React matter?+
If you're weighing React for a new site, auditing a competitor's stack, or figuring out why a prospect's website looks the way it does, the platform choice drives everything downstream: hosting cost, SEO control, performance ceiling, and migration pain later. We've fingerprinted React on 30 live sites in our database, so the answers here are grounded in real scan data — not marketing copy.
How do we detect React?+
Our scanner checks for these signals: react.development.js or react.production.min.js in page scripts; __REACT_FIBER_TRACING__ or __reactFiber attributes in DOM; React DevTools hook detection in window object; Technology stack entry listing React as the framework; JSX-compiled output patterns in page JavaScript bundles. Each match contributes to a confidence score, and the full evidence tiers are documented at /how-scores-work.
How many websites using React are in the database?+
We've fingerprinted 30+ live sites built with React across our scan dataset. The list refreshes as new scans come in.
What are the typical characteristics of a React website?+
Declarative, component-based UI architecture. Virtual DOM for efficient diffing and DOM updates. Unidirectional data flow with state and props. Massive ecosystem of hooks, libraries, and tools. JSX syntax combining JavaScript and HTML-like markup. Used both as a single-page app library and with SSR frameworks
Related Tools & Technologies
Other website builders and platforms we detect
Ready to put React detection to work?
You now know what React is, why it matters, how to spot it, and where the detection signals come from. The next step is using that knowledge on a real URL — yours, a competitor's, or a prospect's.