What is TypeScript and should I use it?

TypeScript is JavaScript with type checking. It catches bugs before they reach production by ensuring your code handles data correctly — if a function expects a number and you pass a string, TypeScript tells you at build time, not when a user hits the error in production.

Should you use it? For any business-critical web application: yes. The initial productivity cost (10-15% slower to write) is paid back by fewer runtime bugs, better IDE autocompletion, easier refactoring, and safer onboarding for new developers.

For a simple marketing site with minimal JavaScript: probably overkill. If your site is mostly HTML and CSS with a contact form, vanilla JavaScript is fine.

The industry has decided: TypeScript adoption in new projects is above 80% as of 2026. All major frameworks (Next.js, React, Angular, Vue, Svelte) have first-class TypeScript support. Most npm packages ship types. Not using TypeScript in a new project requires justification, not the other way around.

The learning curve is real but manageable. A JavaScript developer can be productive in TypeScript within a week. Mastering advanced types (generics, mapped types, conditional types) takes months but isn't necessary for most application code.