$ sudo npm install webpagetest
$ sudo npm install -g webpagetest

If want to update the webpagetest package execute the command as below,

$ sudo npm update webpagetest

Update package globally,

$ npm install -g webpagetest

Git clone:

$ sudo  git clone https://github.com/rektide/webpagetest.git

$ sudo  npm install -g ./webpagetest

webpagetest@0.3.7 /usr/lib/node_modules/webpagetest

How to remove webpagetest package :

You can uninstall or remove this package from your node_modules run the command as below,

$ sudo npm uninstall webpagetest

Basic Information of webpagetest NPM Package: