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How to run TypeScript files from command line?

You can run TypeScript files from the command line by compiling them to JavaScript with the tsc (TypeScript compiler) and then running the resulting JavaScript with node. Alternatively, you can use tools like ts-node to execute TypeScript directly without a separate compile step.

Below are the most common approaches:

1. Using tsc and node

  1. Install TypeScript (globally or in your project): 
    npm install -g typescript
# or, locally:
npm install --save-dev typescript
  2. Compile your .ts file to .js: 
    tsc myFile.ts
# Generates myFile.js (and possibly a .d.ts if configured)
  3. Run the generated JavaScript with node: 
    node myFile.js

This approach separates compilation (tsc) from execution (node).

Example

tsc main.ts    # produces main.js
node main.js   # runs the compiled JS

2. Using ts-node (Run TS directly)

  1. Install ts-node (and TypeScript, if not installed): 
    npm install -g ts-node typescript
# or, locally:
npm install --save-dev ts-node typescript
  2. Run your .ts file directly: 
    ts-node myFile.ts

ts-node compiles your TypeScript on the fly and executes it immediately (like a REPL for TS).

Example

ts-node main.ts

No separate .js file is needed—very convenient for quick scripts or development workflows.

3. Using npx (No Global Installs)

If you have TypeScript and ts-node installed locally in a project, you can use npx:

npx tsc main.ts    # compiles with local tsc
npx ts-node main.ts

This runs the local versions without installing them globally.

4. Typical Project Setup

  1. A tsconfig.json file configures how TypeScript compiles your code (target version, strictness, outDir, etc.).
  2. You can have npm scripts in your package.json like: 
    {
  "scripts": {
    "build": "tsc",
    "start": "ts-node src/main.ts"
  }
}
  3. Then simply run: 
    npm run build   # compiles
npm start       # runs via ts-node

5. Summary

  • Option A: Compile with tsc, then run the resulting .js with node.
  • Option B: Use ts-node to run .ts files directly for convenience (no separate .js needed).
  • Option C: Combine with npm scripts or npx for local usage and project automation.

Bonus: Strengthen Your JavaScript (and TypeScript) Fundamentals

TypeScript builds on core JavaScript concepts. If you want to deepen your JS knowledge—covering prototypes, closures, async patterns, etc.—consider the Grokking JavaScript Fundamentals course by DesignGurus.io. This foundation translates directly to writing better, more maintainable TypeScript code.

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