QUESTION: What is transpilation?

The JavaScript world is evolving at an incredible pace, and language standards are updated almost annually, adding new syntactic constructs, methods, and features. However, users often run outdated browsers that do not understand modern syntax, leading to critical errors on websites. Transpilation is the process of converting new JS into old JS, ensuring full compatibility and stable application performance on any device. Transpilers analyze modern code (such as ES6+ syntax with arrow functions, classes, and destructuring) and rewrite it into standard ES5, which is supported even by the most archaic browsers.

The most famous and popular transpilation standard in the web development world is Babel. It allows developers to use the most advanced language features today without waiting for all users to update their browsers. In addition, TypeScript also transpiles code: this popular strictly typed language is not executed directly by the browser; its compiler (tsc) first converts types and modern syntax into plain, clean JavaScript. It is important to understand that transpilation modifies the code syntax itself, but it does not add missing global objects or methods—such as Promise or array methods—to older browsers. To solve this problem, transpilation often goes hand in hand with using polyfills for new APIs, creating a reliable foundation for cross-browser development.