What is React JS?

React is a JavaScript library for building user interfaces. It was originally created at Facebook (now Meta) in 2013, and it introduced a component-based architecture that changed how developers think about building web applications.

Instead of writing HTML pages and sprinkling JavaScript on top, React lets you build self-contained components — reusable pieces of UI that manage their own state and compose together into complex applications. A button, a navigation bar, a product card — each is a component that can be tested, reused, and maintained independently.

The core ideas that made React popular — the virtual DOM for efficient updates, JSX for writing UI in JavaScript, and one-way data flow for predictability — are still at its heart. But the library has evolved dramatically since then.

The React Foundation — React is no longer owned by Meta

The single biggest change in React's history happened in February 2026: Meta transferred ownership of React, React Native, and supporting projects like JSX to the newly formed React Foundation, an independent entity under the Linux Foundation.

This means React's governance is now vendor-neutral. The foundation's board includes representatives from Amazon, Callstack, Expo, Huawei, Meta, Microsoft, Software Mansion, and Vercel — with plans to expand further.

Seth Webster serves as the foundation's executive director. The technical governance remains separate from the business board — meaning day-to-day decisions about React's codebase are still made by the core team of engineers who build it, not by corporate representatives.

React 19 — what actually changed

React 19 was released in December 2024, followed by React 19.1 in June 2025 and React 19.2 in October 2025. Together, these releases represent the most significant evolution of React since hooks were introduced in version 16.8.

Key features at a glance

React 19 release timeline

The React Compiler — automatic optimisation

One of the most common complaints about React has been the performance ceremony — wrapping components in React.memo, memoising values with useMemo, and stabilising callbacks with useCallback. In large codebases, this boilerplate adds up fast.

The React Compiler, which went stable at React Conf in October 2025, solves this. It analyses your component code at build time and automatically inserts the optimisations where they're needed. You write normal React code; the compiler handles the rest.

// Before: manual memoisation everywhere
const ProductList = memo(({ products, onSelect }) => {
  const sorted = useMemo(() =>
    products.sort((a, b) => b.price - a.price),
    [products]
  );
  const handleClick = useCallback((id) =>
    onSelect(id),
    [onSelect]
  );
  return sorted.map(p =>
    <Item key={p.id} onClick={handleClick} />
  );
});

// After: React Compiler handles it automatically
function ProductList({ products, onSelect }) {
  const sorted = products.sort((a, b) => b.price - a.price);
  return sorted.map(p =>
    <Item key={p.id} onClick={() => onSelect(p.id)} />
  );
}

Server Components and Server Actions

React Server Components let you run components entirely on the server. They can access databases, file systems, and internal APIs directly — then send only the rendered HTML to the browser. No JavaScript bundle is shipped for server components.

Server Actions take this further by letting you define server-side functions that can be called directly from client components — replacing the traditional pattern of separate API routes, client-side fetch calls, loading states, and error handling.

// A Server Component — runs on the server, zero client JS
async function CourseList() {
  const courses = await db.courses.findMany();
  return (
    <ul>
      {courses.map(c => <li key={c.id}>{c.name}</li>)}
    </ul>
  );
}

// A Server Action — replaces API routes
'use server'
async function enrollStudent(formData) {
  const courseId = formData.get('courseId');
  await db.enrollments.create({ courseId, studentId: auth.userId });
  redirect(`/courses/${courseId}`);
}

The State of React 2025 survey shows that Server Components are now adopted in roughly 45% of new projects. They're particularly impactful for content-heavy sites, dashboards, and any application where initial load performance matters.

The React ecosystem in 2026

React itself is just the UI layer. The real power comes from the ecosystem of frameworks, libraries, and tools built around it. Here's what the landscape looks like today:

Frameworks

Next.js remains the dominant full-stack React framework, with built-in Server Components, App Router, and edge deployment. React Router v7 absorbed many features from Remix and is the go-to for SPAs that don't need a full framework. Astro has gained traction for content-heavy sites using React components with partial hydration.

State management

A notable trend from the State of React 2025 survey: 34% of respondents don't use any external state management library, relying entirely on React's built-in APIs. For those that do, Zustand and TanStack Query lead the pack, with Redux Toolkit still widely used in enterprise codebases.

Styling

CSS Modules (65%) and Sass (59%) remain the most popular styling approaches. Tailwind CSS continues to grow, particularly in new projects. The runtime CSS-in-JS libraries like styled-components have declined as developers shift toward zero-runtime solutions.

React Native

React Native 0.83 (released December 2025) ships with React 19.2 support and adds network inspection and performance tracing to DevTools. The New Architecture (Fabric renderer + TurboModules) is now the default, delivering significant performance improvements for mobile apps.

React vs the competition in 2026

React isn't the only option. Here's an honest comparison with the other major players:

React's main advantage isn't any single feature — it's the combination of a massive ecosystem, strong job market, cross-platform reach with React Native, and now independent governance that gives companies long-term confidence.

Why companies still choose React

What's coming next for React

Based on the React team's public roadmap and recent conference talks, here's what to expect:

Getting started with React in 2026

If you're starting a new React project today, the recommended approach depends on what you're building:

Full-stack web app: Use Next.js with the App Router. It gives you Server Components, Server Actions, and the React Compiler out of the box.

npx create-next-app@latest my-app
cd my-app
npm run dev

Single-page app (SPA): Use Vite with React Router v7 for a lightweight, fast development experience.

npm create vite@latest my-spa -- --template react-ts
cd my-spa
npm install react-router
npm run dev

Mobile app: Use Expo with React Native for the fastest path to iOS and Android.

npx create-expo-app my-mobile-app
cd my-mobile-app
npx expo start