React
JSX
A syntax that lets you write HTML-like markup directly inside JavaScript.
Reviewed by the RadarTrek editorial team · June 2026
JSX (JavaScript XML) lets React developers describe what the UI should look like using HTML-like tags inside regular JavaScript code, then compiles it down to plain JavaScript function calls. It's how React components combine logic and markup in one place instead of separate template files.
Why it matters
- —JSX is the first thing that looks unfamiliar to HTML developers learning React — but it's just JavaScript underneath.
- —Curly braces {} inside JSX let you drop any JavaScript expression straight into your markup.
- —Every React component you'll ever write returns JSX (or null).
Where to learn this
🎓
JSX: HTML in JavaScript
React Fundamentals course
This is the exact lesson that covers this term in depth — with examples, diagrams, and a hands-on exercise.