When to use 'npm start' and when to use 'ng serve'?

Question

ng serve serves an Angular project via a development server

 

npm start runs an ar

Answer 1

For a project that's using the CLI, you will usually use ng serve. In other cases you may want to use npm start. Here the detailed explanation:

ng serve

Will serve a project that is 'Angular CLI aware', i.e. a project that has been created using the Angular CLI, particularly using:

ng new app-name

So, if you've scaffolded a project using the CLI, you'll probably want to use ng serve

npm start

This can be used in the case of a project that is not Angular CLI aware (or it can simply be used to run 'ng serve' for a project that's Angular CLI aware)

As the other answers state, this is an npm command that will run the npm command(s) from the package.json that have the identifier 'start', and it doesn't just have to run 'ng serve'. It's possible to have something like the following in the package.json:

   "scripts": {
     "build:watch": "tsc -p src/ -w",
     "serve": "lite-server -c=bs-config.json",
     "start": "concurrently \"npm run build:watch\" \"npm run serve\""
     ...
   },
   "devDependencies": {
     "concurrently": "^3.2.0",
     "lite-server": "^2.2.2",

In this case, 'npm start' will result in the following commands to be run:

concurrently "npm run build:watch" "npm run serve"

This will concurrently run the TypeScript compiler (watching for code changes), and run the Node lite-server (which users BrowserSync)