How to share data between browser tabs?

I have to develop a program where I need to get the event from server and want to update the web page.

e.g. I have multiple browser tab opened for chat and each chat page have its own thread to fetch the event from the server but once the one thread among the chat will fetch the event than other get empty stack of event due to extract by the another Chat page.

So, here my concern is to share event with multiple chat pages without refreshing the page.

Sound like you could use postMessage to have the tab that gets the message share it with all the other pages on your domain.

postMessage(JSON.stringify({chatmsg: someVarFromServer}), "http://www.mydomain.com");

Have other chat pages listen for message events:

window.addEventListener("message", receiveMessage, false);

function receiveMessage(event) {
    // reject foreign messages!
    if (event.origin !== "http://www.mydomain.com") return;

    var message = JSON.parse(event.data).chatmsg;

    // this other page now has the message
}