There is a load event, which will fire AFTER the page is loaded. You can listen to the event:
window.addEventListener('load', function() {
console.log('All assets are loaded');
alert ("This is an alert MSG");
})
W3Schools
w3schools.com › howto › howto_js_alert.asp
How To Create an Alert Message Box
Alert messages can be used to notify the user about something special: danger, success, information or warning.
W3Schools
w3schools.com › jsref › met_win_alert.asp
Window alert() Method
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.
Videos
38:55
Alert Notification using HTML, CSS and Javascript - YouTube
14:33
Dynamic Content for Alert Notification (HTML, CSS, JS) - YouTube
27:07
Notification Alert Messages using HTML CSS and Javascript || Alert ...
22:27
How to create a custom alert box - with HTML, CSS ...
12:14
How to Create Custom Alert Box using Javascript Tutorial - YouTube
University of Washington
washington.edu › accesscomputing › webd2 › student › unit5 › module2 › lesson1.html
Lesson 1: Using JavaScript to Show an Alert
However, we could trigger it using other events instead. For example, we might to display the alert only if a user clicks on a button. Try this: Remove the onload="showAlert()" attribute from the <body> element. Add the following HTML <button> element anywhere within the body of your web page:
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › API › Window › alert
Window: alert() method - Web APIs | MDN - Mozilla
window.alert() instructs the browser to display a dialog with an optional message, and to wait until the user dismisses the dialog.
GeeksforGeeks
geeksforgeeks.org › html › html-dom-window-alert-method
HTML DOM Window alert() Method - GeeksforGeeks
... <!DOCTYPE html> <html lang="en"> ... green;"> GeeksforGeeks </h1> <p> For displaying the alert message, double click the "Show Alert Message" button: </p> <button ondblclick="myalert()"> Show Alert Message </button> <script> ...
Published July 11, 2025
Edureka
edureka.co › blog › javascript-alert
Alert() in JavaScript | How to Create an Alert Message Box | Edureka
February 25, 2025 - It displays a specified message along with an OK button and is generally used to make sure that the user gets the information. It returns a string which represents the text to display in the alert box. Let’s take an example and see how to create an alert in JavaScript: <!DOCTYPE html> <html> <head> <title> Alert() Method in JavaScript </title> <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" data-wp-preserve="<style> h1 { color: Blue; } h2 { font-family: Impact; } body { text-align: center; } </style>" data-mce-resize="false" data-mce-placeholder="1"
Top answer 1 of 5
3
There is a load event, which will fire AFTER the page is loaded. You can listen to the event:
window.addEventListener('load', function() {
console.log('All assets are loaded');
alert ("This is an alert MSG");
})
2 of 5
0
You can use setTimeout() for this
<html>
<head>
<title>Hello, World !</title>
</head>
<body>
<h1>I am learning JavaScript.</h1>
<div id="Content">
<p>This is a paragraph tag. Here the content of html.</p>
</div>
<script>
setTimeout(()=>{
alert(" This is alert message.")
},2000)
</script>
</body>
</html>
W3Schools
www-db.deis.unibo.it › courses › TW › DOCS › w3schools › howto › howto_js_alert.asp.html
How To Create an Alert Message Box
Indicates a warning that might need attention. <div class="alert"> <span class="closebtn" onclick="this.parentElement.style.display='none';">×</span> This is an alert box. </div> If you want the ability to close the alert message, add a <span> element with an onclick attribute that says ...
W3Schools
w3schools.com › JS › tryit.asp
W3Schools Tryit Editor - JavaScript Alert
❯Run Code Ctrl+Alt+R Save Code Ctrl+Alt+A Change Orientation Ctrl+Alt+O Change Theme Ctrl+Alt+D Go to Spaces Ctrl+Alt+P
Bootstrap
getbootstrap.com › docs › 4.0 › components › alerts
Alerts · Bootstrap
Skip to main content There's a newer version of Bootstrap! ... Provide contextual feedback messages for typical user actions with the handful of available and flexible alert messages. Alerts are available for any length of text, as well as an optional dismiss button. For proper styling, use one of the eight required contextual classes (e.g., .alert-success). For inline dismissal, use the alerts jQuery plugin.
YouTube
youtube.com › watch
How to Add an Alert Box to Your Websites with HTML & CSS - YouTube
View the SOURCE CODE 👇https://dcode.domenade.com/tutorials/how-to-add-an-alert-box-to-your-website-using-html-and-cssGoogle Material Symbols & Fonts 👇https...
Published February 5, 2025
Uw
projects.accesscomputing.uw.edu › webd2 › student › unit5 › module2 › lesson1.html
Lesson 5.2.1: Using JavaScript to Show an Alert
However, we could trigger it using other events instead. For example, we might to display the alert only if a user clicks on a button. Try this: Remove the onload="showAlert()" attribute from the <body> element. Add the following HTML <button> element anywhere within the body of your web page:
SheCodes
shecodes.io › athena › 39031-how-to-create-an-alert-after-clicking-a-button-using-javascript
[JavaScript] - How to create an alert after clicking a button using JavaScript
Learn how to use JavaScript to create an alert after a button click in HTML
Codecademy
codecademy.com › forum_questions › 512d28a06918338f2300e9ea
How to make a html button clickable and to show alert on it ? | Codecademy
<script> function clickAlert() { alert("Alert!"); } </script> <input type="button" onclick="clickAlert()" value="Click-2-Alert">
TutorialsPoint
tutorialspoint.com › how-to-create-alert-messages-with-css
How to create alert messages with CSS?
To create alert messages with CSS, the code is as follows − · <!DOCTYPE html> <html> <head> <style> body{ font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; } .alertMessage { padding: 20px; background-color: #f44336; color: white; font-size: 20px; } .close{ margin-left: 15px; color: white; font-weight: bold; float: right; font-size: 22px; line-height: 20px; cursor: pointer; transition: 0.3s; } .close:hover { color: black; } </style> </head> <body> <h1>Alert Message Example</h1> <div class="alertMessage"> <span class="close" onclick="this.parentElement.style.display='none';">Ã</span> <strong>This cannot be revered!</strong> Your account will be deleted.
Top answer 1 of 6
53
You can use all Unicode characters and the escape characters \n and \t. An example:
document.getElementById("test").onclick = function() {
alert(
'This is an alert with basic formatting\n\n'
+ "\t• list item 1\n"
+ '\t• list item 2\n'
+ '\t• list item 3\n\n'
+ '▬▬▬▬▬▬▬▬▬ஜ۩۞۩ஜ▬▬▬▬▬▬▬▬▬\n\n'
+ 'Simple table\n\n'
+ 'Char\t| Result\n'
+ '\\n\t| line break\n'
+ '\\t\t| tab space'
);
}<!DOCTYPE html>
<title>Alert formatting</title>
<meta charset=utf-8>
<button id=test>Click</button>Result in Firefox:
You get the same look in almost all browsers.
2 of 6
26
alert() is a method of the window object that cannot interpret HTML tags
Quackit
quackit.com › javascript › javascript_alert_box.cfm
JavaScript Alert Box
The JavaScript alert box is useful for alerting your users to something important. When a JavaScript alert box is triggered, a small box will pop up and display the text that you specify in your JavaScript code. You create a JavaScript alert box by calling the built-in JavaScript alert() function. ...
Top answer 1 of 6
1
You look like you are trying to use Bootstrap's 'alert' classes (e.g. 'success'). http://getbootstrap.com/components/#alerts
The only way to make that a semantic element like <alert /> that I know of is something like AngularJS: http://angular-ui.github.io/bootstrap/#/alert
In this case, it is all styled by Bootstrap, or whatever Bootstrap theme you are using.
2 of 6
0
First there is not an HTML tag alert. you can create an alert with javascript.
You cannot add style to an alert as it is produced by the browser by default.
Have a look to this post: How do I style the alert box with CSS?
Tutorialdeep
tutorialdeep.com › knowhow › html faqs › how to create jquery alert message box in html
How to Create or Add jQuery Alert Message Box in HTML
April 4, 2021 - In this tutorial, learn how to create or add a jQuery alert message box in HTML content. The short answer is to use the jQuery alert() and pass the content as t
Top answer 1 of 8
18
Yes you need javascript. The simplest way is to just put this at the bottom of your HTML page:
<script type="text/javascript">
alert("Hello world");
</script>
There are more preferred methods, like using jQuery's ready function, but this method will work.
2 of 8
4
You can use a variety of methods, one uses Javascript window.onload function in a simple function call from a script or from the body as in the solutions above, you can also use jQuery to do this but its just a modification of Javascript...Just add Jquery to your header by pasting
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
to your head section and open another script tag where you display the alert when the DOM is ready i.e. `
<script>
$("document").ready( function () {
alert("Hello, world");
});
</script>
`
This uses Jquery to run the function but since jQuery is a Javascript framework it contains Javascript code hence the Javascript alert function..hope this helps...