history.replaceState() operates exactly like history.pushState() except that replaceState() modifies the current history entry instead of creating a new one. This method is useful when you want to update the URL or the state object for the current history.
It has 3 parameters: state object, page title, and a url.
state object:
It is a JavaScript object associated with the updated history entry done by replaceState() method. The state object can be anything but max of 640k characters in size.
title:
This parameter is currently ignored. You can pass a blank string at this place.
URL:
Pass the updated URL in this parameter.
Learn about pushState() method here.
Learn more about replaceState() method here.
Example of replaceState() method:
var stateObj = { foo: "bar" };
history.replaceState(stateObj, "Title of the page", "new-page-url.html");