JavaScript or TypeScript: which should you choose?

Both become JavaScript at runtime

TypeScript adds static analysis to JavaScript. Browsers do not execute its types; the compiler reports many problems early and removes type syntax before runtime.

A contract tools can understand

type Project = { id: string; title: string };

function openProject(project: Project) {
  return `/editor?project=${project.id}`;
}

A simple decision rule

• For a tiny experiment, JavaScript has less initial friction.
• For a growing product, TypeScript reduces the cost of change.
• On a team, types become living API documentation.

TypeScript does not replace tests; it catches an important class of mistakes earlier and more cheaply.