I don't install packages globally. Usually each package I install belongs to a project. So I install it locally as a dependency. If a package offers CLI functionality I add it in package.json under scripts section.

{
  ...,
  "scripts": {
    "webpack": "webpack",
    "start": "node .",
    ...
  },
  ...,
}

Now I can run its CLI features. npm run webpack. If needed I add bash or zsh aliases to get rid of ever repeating npm run prefix. I do this because each package targets a specific minimum node version. When ever I am forced or willing to upgrade node I must not care for globally installed packages unless installed globally, of cause. Some few CLI tools require other global CLI tools. Only in his case I am forced to install a package gloabaly. To not forget about such global package I add an echo script to my package.json which yells about this global package and I add this echo to all scripts 'yell && <script name>`. Now I can't forget to frequently search for non global alternatives.

Additionally when installing a package locally I can reference it in import or require statements fairly easily. No construct required to check if the global package exists and matches the expected version or a version range. I see it often that in tutorials authors recommend installing gulp and webpack globally but then require either one or both packages in a local script. This can pay back badly when you upgrade node or npm or any plugin you were told to install.

PS: @sandeep I hacked this message on mobile :-)

As Lars said, it depends. If it's a CLI tool or something similar, it's usually installed globally (npm install -g). Your project's dependencies such as Express, passport, body-parser, ejs etc are installed locally (npm install).

I decide. Sometimes global and mostly local. Thinks like ts-node, ava, typescript are global and local. Than other thinks like expressjs, body-parser are always local.

So when a package has global use I install it global and when not I install it lokal.

What @fibric says. Additionaly, pay attention to what IDE do you use: sometimes they require a package to be installed specifically locally or globally.

• Local install (default): puts stuff in ./node_modules of the current package root.
• Global install (with -g): puts stuff in /usr/local or wherever node is installed.
• Install it locally if you're going to require() it.
• Install it globally if you're going to run it on the command line.
• If you need both, then install it in both places, or use npm link.

reference : docs.npmjs.com/files/folders