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Web & Frontend
React
Latestv19.2.7Updated Jun 1, 2026
Overview
React is a free and open-source front-end JavaScript library that aims to make building user interfaces based on components more "seamless". It is maintained by Meta and a community of individual developers and companies. According to the 2025 Stack Overflow Developer Survey, React is one of the most commonly used web technologies.
Read moreHow it works
jsx
function Counter() {
const [n, setN] = useState(0);
return <button onClick={() => setN(n + 1)}>{n}</button>;
}The flow
Step by step, from source to running.
- 1Components return JSX
- 2React builds a virtual DOM
- 3Diffing finds minimal changes
- 4The real DOM is patched
Latest changes
v19.2.7 · Jun 1, 2026
- Fixed missing FormData entries in Server Actions which regressed in 19.2.6