React
Meta's open-source JavaScript library for building user interfaces
React is an open-source JavaScript library for building user interfaces - the part of a website people see and interact with. Created by Meta (then Facebook) in 2013, it now powers millions of websites and web apps.
React is a JavaScript library (a reusable collection of code) for building user interfaces. Strictly speaking, it is not a framework: a framework dictates the whole structure of a project, while React solves one job - the UI - and leaves the other decisions to the team. That is why React is usually paired with additional tools, most commonly the Next.js framework, which adds routing, data handling and server rendering.
React's core idea is components: the interface is split into small, reusable blocks such as a button, a menu or a product card. Each component holds its own 'state' (its current data - for example, how many items are in the cart), and when the state changes, React updates only the affected part of the screen instead of reloading the page. This keeps interfaces fast and keeps the code manageable as a project grows.
React's popularity comes from its simple mental model, a huge ecosystem and Meta's ongoing backing: Facebook, Instagram, Netflix and Airbnb all run on it. Its sibling, React Native, applies the same principles to mobile, letting one team ship both iOS and Android apps. In Stack Overflow's annual developer surveys, React has ranked among the most-used front-end technologies for years.
Classic client-side React apps used to be a challenge for SEO, because content was assembled in the browser and search engines could see it late or incompletely. Frameworks like Next.js solve this with server-side rendering: pages are delivered as ready-made HTML that Google indexes without issues. React is not fading - modern versions keep evolving with features like Server Components, and it remains one of the web's foundational technologies.
Frequently asked questions
React is an open-source JavaScript library for building user interfaces, created by Meta (Facebook) in 2013. It is used for everything from simple business websites to complex platforms like Facebook, Instagram and Netflix. Today it is one of the most widely used front-end technologies in the world.



