node-prune is a small tool to prune unnecessary files from ./node_modules, such as markdown, typescript source files, and so on. Primarily built for Up which lets you deploy serverless web applications in seconds.

From gobinaries.com:

$ curl -sf https://gobinaries.com/tj/node-prune | sh

From source:

$ go get github.com/tj/node-prune

In your app directory:

$ node-prune

files total 27,330
files removed 3,990
size removed 13 MB
   duration 200ms

Somewhere else:

$ node-prune path/to/node_modules

files total 27,330
files removed 3,990
size removed 13 MB
   duration 200ms

Or add to the package.json scripts field

  "scripts": {
    "postinstall": "node-prune"
  }