What is the best technology for concurrent webpage sessions?

What is the recommended technology or technologies to use in order to make a webpage that automatically updates the screen depending on a value change in a database?

For example:

There is a webpage with a button. When the button is pressed, a corresponding value in a database is changed from off to on. When this is completed, the database is checked again and the button on the webpage changes to the corresponding state (either on or off).

Several webpages may be open on different devices and they must also change.

I have looked into Node.js with Express and Socket.io but it seems to have relatively little documentation and I was wondering if this can all just be accomplished in another way since Javascript is pretty slow (I think).

thanks.