Can we use this code online?

[RuyiLi]

If I were to make a website with all these, would it work?

[staeff]

Yes, the only requirement ist Node.js. With the following steps I could run this example:

git clone https://github.com/rauchg/chat-example.git
cd chat-example/
npm install
node index.js

See also https://github.com/rauchg/chat-example/pull/5, where someone has created a version of the example that runs on Heroku