Real time - Which is the best way?

How large is your user base?

Depending on what kind of functionality, how large your active user base is,  and how 'real-time' you need it to be, you can choose between polling or websockets.

At the end of the day, websockets will scale much better than polling and is more real-time. If you're wanting to go the easy route of websockets, I'd recommend nodejs with something like socket.io. If you're wanting to build an app that can scale to the roof, I'd recommend using Elixir + phoenix.

My website still under construction, I'm at the point to do the real time. I know that websockets are not available on all browser, is it a problem?

However, I'll see elixir and phoenix because I don't know them.
Obviously I'm using Codeigniter to build the website's system.

I'm pretty sure things like Socket.io have fallbacks for browser issues as does phoenix.

Phoenix and Elixir is an entirely different world of programming so it's a lot more difficult to do if you haven't done anything outside of PHP and Javascript, but it's also how Whatsapp was able to handle billions of real time notifications on just a handful of servers.

Obviously I want learn something new ^_^, but I saw and I must say that Elixir and Phoenixframework are really hard for me ahah!