How to install npm -g on offline server

try npmbox, it is the new name of npmzip which will allow you to install offline npm packages by one file

You can install stuff from a tarball file, check out the npm documentation. You can find the URL of the forever tarball with npm view forever dist.tarball and download that. Try something like this:

curl -so forever.tar.gz `npm view forever dist.tarball 2> /dev/null`
npm install ./forever.tar.gz -g

But you might have to do this for all of the dependencies as well. There might be a better way but this is what I've found in my search.