Do not sudo npm

Using root privileges with npm is not recommended, we'll go through the reasons. Avoid common pitfalls and learn the options for a proper installation of npm.

Even when the documentation says that you can install Node and npm using sudo, its not the best idea. If you do that, any future global installations with npm install -g will need root permissions. At some point, doing that will cause you to run into issues during package installations, you'll see errors like:

npm ERR! code EACCES

NPM provides instructions on how to fix things when global installations go wrong. You can either reconfigure npm or change permissions in different paths. It will usually be a not too complicated solution, but also each system/user might need to change an extra path or a slightly different path...

Also, if you update your operating system or npm, there is a chance that the file paths and permissions configured with the guide above will be overriden and you'll have to re-do them.

You can completely avoid those incantations if you never issue a sudo command.

Why not?

You should not run applications with root privileges if its not necessary. Node and npm can do their work just perfectly fine without admin powers.

Running a server

If you are running a server with root privileges and it gets hacked through a vulnerability in your code, the attacker will have total control over your machine.

sudo node server.js # bad

If you say:

I need access to port 80 so that I can serve HTTP responses and only root can listen to it.

What needs to be done is redirect the traffic to a port that can be enabled without root privileges and have your Node application listen to that port, not run the whole thing with sudo.

You can redirect ports with iptables or a reverse proxy like Nginx, using one of those tools allows you to send the traffic from port 80 to whatever port you chose for your Node application.

Installing packages

Don't install packages with root privileges.

Packages can run arbitrary scripts, which makes sudoing a package manager command as safe as a chainsaw haircut.

– @izs, npm core

This situation was addressed with safe sudo behavior, but there is a chance that some packages will be "broken" and still execute code with root privileges.

Install related lifecycle scripts are rare, as we heavily discourage their use, but there are some out there.

— @ReBeccaOrg, npm core

Although the situatuion has been handled, lets err on the side of caution and avoid using sudo.

Avoid common pitfalls

Find trouble elsewhere, save yourself from some pain here. Using sudo is likely to give you package installation headaches. As I write this, there are 1,108 StackOverflow (SO) questions related to sudo npm. Many Node.js SO posts can be boiled down to:

npm didn't work so I tried again using sudo and broke my install

I'm aware that many of them will not be exactly a "I can't install X package" type of question, but if we cut that number to a third it still is a crazy amount! Consider that very popular SO questions have 3 to 4 duplicates.

Keep it simple

The first two points might not be of utter importance if there is a single user in your system and its not a production environment. However, the third point remains indisputably a hurdle that you want to avoid; you don't want to spend time fixing a package manager that you accidentally broke.

Install npm properly

Install Node and npm with one of this options:

1. Manually download and install Node binaries from nodejs.org.
2. Use one of the techniques listed in install node and npm without sudo by @izs.
3. Use Node Version Manager (NVM).

What I always do is use nvm because with a single command I can get the ball rolling. I have never had a problem with it. And for production I download and manually install the Node version that I need.