JavaScript has three kind of popup boxes: Alert box, Confirm box, and Prompt box.

The alert() method displays an alert box with a message and an OK button. The alert() method is used when you want information to come through to the user.

Feb 18, 2025 · The window.postMessage() method safely enables cross-origin communication between Window objects; e.g., between a page and a pop-up that it spawned, or between a page and an iframe embedded within it.

Nov 13, 2015 · You can push data from the server to the browser via Server Side Events. This is essentially a unidirectional stream that a client can "subscribe" to from a browser. From here, you could just create new Notification objects as SSEs stream into the browser:

Jul 2, 2023 · This tutorial will walk through examples of how to display messages in HTML Javascript. Free code download included.

Apr 10, 2025 · Learn about the message event, including its type, syntax, and properties, code examples, specifications, and browser compatibility.

Oct 4, 2023 · window.alert() instructs the browser to display a dialog with an optional message, and to wait until the user dismisses the dialog. Under some conditions — for example, when the user switches tabs — the browser may not actually display a dialog, or may not wait for the user to dismiss the dialog.

JavaScript provides built-in global functions to display popup message boxes for different purposes. alert(message): Display a popup box with the specified message with the OK button. confirm(message): Display a popup box with the specified message with OK and Cancel buttons.

JavaScript can "display" data in different ways: Writing into an HTML element, using innerHTML or innerText. Writing into the HTML output using document.write(). Writing into an alert box, using window.alert(). Writing into the browser console, using console.log(). To access an HTML element, you can use the document.getElementById(id) method.

Jun 7, 2021 · Learn how to create alert, prompt and confirm dialog boxes using JavaScript along with syntax, example code and how it looks on a browser. Alert box is to show a message, prompt dialog box is to show a customized text message based on user input and a confirm dialog box is to confirm a user action on a webpage.