Using server-sent events
developer.mozilla.org
The server-sent event API is contained in the EventSource interface; to open a connection to the server to begin receiving events from it, create a new EventSource object with the URL of a script that generates the events. For example:

Here’s a simpler alternative to WebSockets I recently learned about. It’s really easy to use and allows you to make a page live while keeping most of the logic on the server. I used it in a work project recently and it was a breeze.