React

React is an open-source JavaScript library for building user interfaces. It structures applications around reusable components that describe their own appearance and behavior.

Meta released React as open-source software at JSConf US in May 2013. The project uses the MIT license and is developed publicly through its GitHub repository.

React focuses on the user-interface layer rather than providing a complete application stack. Teams commonly add frameworks or libraries for routing, data fetching, authentication, testing, and deployment.

React supports declarative components, JSX, one-way data flow, local state, context, and reusable Hooks. Its reference documentation also includes built-in APIs for lazy loading, memoization, transitions, caching, and testing.

The React DOM package provides browser rendering APIs, client rendering, server rendering, and static HTML generation. React also supports Server Components and related directives through compatible frameworks and bundlers.

The official React documentation recommends production frameworks such as Next.js and React Router for applications requiring routing, data fetching, code splitting, or full-stack rendering. Build tools including Vite, Parcel, and Rsbuild support projects built from scratch.

React is distributed as free, open-source software under the MIT license. It has no subscription plans, usage charges, or paid product tiers.

Development teams may incur separate costs for hosting, commercial development tools, cloud services, framework support, or third-party integrations. Those costs aren’t charged by React itself.

Pros

• Free MIT-licensed software with public source code.
• Reusable components and Hooks support modular interface development.
• Provides browser, server, and static rendering APIs.
• Works with multiple frameworks, bundlers, runtimes, and deployment models.
• Offers extensive official documentation and an established open-source ecosystem.

Cons

• React doesn’t provide a complete application architecture by itself.
• Routing, data fetching, forms, and state management often require additional choices.
• Server Components require compatible framework or bundler integration.
• Teams must manage JavaScript tooling, dependency versions, and build configuration.
• React’s flexibility can create architectural inconsistency across projects.

Comparable frontend technologies include Vue, Angular, Svelte, and Solid. Vue offers a progressive component framework, Angular provides an integrated application framework, and Svelte compiles components during the build process.

React is also commonly compared with Solid for component-based JavaScript interfaces. The best alternative depends on requirements for framework structure, compilation strategy, ecosystem compatibility, and team expertise.

Is React a framework?

React describes itself as a JavaScript library for user interfaces. The official documentation recommends pairing it with a framework for many production applications.

Is React free?

Yes. React is open-source software released under the MIT license, with no React subscription or usage fee.

Does React include routing?

No. React does not include a general-purpose router. React projects commonly use React Router or a framework such as Next.js.

Can React render on the server?

Yes. React DOM includes server and static rendering APIs, while Server Components require compatible frameworks or bundlers.

Does React have an API?

Yes. The React package exposes Hooks, components, built-in APIs, and directives. React DOM provides browser, client, server, and static rendering APIs.

Is Create React App still recommended?

The React team deprecated Create React App for new applications in February 2025. The documentation recommends frameworks or build tools such as Vite, Parcel, and Rsbuild instead.