How to show alert message on page load in JavaScript

Showing an alert message on page load is a great way to grab the attention of your website visitors and inform them about important information.

Fortunately, it's easy to show an alert message using JavaScript when someone visits your website.

In this article, I will discuss how you can use JavaScript code snippets to display custom alerts on page load that are tailored specifically for your needs.

We will also go over some best practices and tips so that you can get the most out of this technique!

Step 1: Create Your Alert Message #

The first step in showing an alert message on page load is creating the actual content of the alert itself. You should create something catchy yet informative so that it stands out from other elements on the webpage and grabs user attention right away!

Step 2: Add Your Code Snippet To The Page Load Event Handler Function#

Once you've created a suitable notification/alert box content; next step would be adding appropriate code snippet inside event handler function which gets triggered whenever someone loads webpage.

Here's sample code example illustrating how one could accomplish such task using plain vanilla javascript language features without any external libraries.

How to show an alert message after 5 seconds#

The first step is to create a function that will display the alert message after 5 seconds have elapsed since the page has loaded.

In the above code, we used two functions; window.onload and setTimeout(). The window object's onload event handler is triggered when all of the content (including images) on the webpage has been completely loaded and rendered by browser engine.

It means our script won't run until everything else is done loading first! The second part of our code uses setTimeout() which takes two arguments; one being what should happen, and then how long do we want it wait before executing?

We specify "5000" milliseconds or five-seconds as our second argument so that's exactly what happens here! Once those five-seconds have expired, then only does our alert box appear with its contents saying "Hello world!".