How to Use the TypeScript Compiler (tsc) to Compile Your Code

TLDR tsc is the TypeScript compiler. It turns your .ts files into .js files that Node.js and browsers can run. Install it with npm install -g typescript . Run tsc to compile your whole project. Run tsc --watch to auto-compile on every file save. Run tsc --noEmit to check for errors without creating any files. What is the TypeScript Compiler? The TypeScript compiler is a tool called tsc . It reads your TypeScript files and turns them into JavaScript files. Your browser and Node.js cannot run TypeScript directly. They only understand JavaScript. So tsc acts as the bridge between what you write and what actually runs. Think of tsc like a spell checker for your code. It finds problems before your code ever runs. Then it produces clean JavaScript output for you. How to Install the TypeScript Compiler You install tsc using npm. There are two ways to do this. Option 1: Global Install (runs anywhere on your computer) npm install -g typescript After install, check it works: tsc --version You will see something like Version 6.0.3 . Option 2: Local Install (recommended for teams) npm install --save-dev typescript Then run it using npx : npx tsc --version Which one should you use? Use a local install for project work. This makes sure everyone on your team uses the same TypeScript version. Use a global install only for quick personal experiments. How to Compile a Single TypeScript File The simplest way to use tsc is to pass it a single file. Create a file called hello.ts : const message : string = " Hello, TypeScript! " ; console . log ( message ); Now compile it: tsc hello.ts This creates a new file called hello.js in the same folder: var message = " Hello, TypeScript! " ; console . log ( message ); Notice that TypeScript removed the : string type annotation. The output is plain JavaScript that Node.js can run. Run the output file: node hello.js # Hello, TypeScript! Important: When you pass a file directly to tsc , it ignores your tsconfig.json . It uses its own default setting