How TO - Alerts
Learn how to create alert messages with CSS.
Alerts
Alert messages can be used to notify the user about something special: danger, success, information or warning.
Create An Alert Message
Step 1) Add HTML:
Example
<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 "when you click on me, hide my parent element" -
which is the container <div> (class="alert").
Tip: Use the HTML entity "×" to create the letter "x".
Step 2) Add CSS:
Style the alert box and the close button:
Example
/* The alert message box */
.alert {
padding: 20px;
background-color: #f44336; /* Red */
color: white;
margin-bottom: 15px;
}
/* The close button */
.closebtn {
margin-left: 15px;
color: white;
font-weight: bold;
float: right;
font-size: 22px;
line-height: 20px;
cursor: pointer;
transition: 0.3s;
}
/* When
moving the mouse over the close button */
.closebtn:hover {
color: black;
}
Try it Yourself »
Many Alerts
If you have many alert messages on a page, you can add the following script to close different alerts without using the onclick attribute on each <span> element.
And, if you want the alerts to slowly fade out when you click on them, add opacity
and transition to the alert class:
Example
<style>
.alert {
opacity: 1;
transition: opacity 0.6s; /* 600ms to fade out */
}
</style>
<script>
// Get all elements with class="closebtn"
var close = document.getElementsByClassName("closebtn");
var
i;
// Loop through all close buttons
for (i = 0; i < close.length; i++) {
// When someone clicks on a close button
close[i].onclick =
function(){
// Get the
parent of <span class="closebtn"> (<div class="alert">)
var div = this.parentElement;
// Set the opacity of div to
0 (transparent)
div.style.opacity = "0";
// Hide the div after 600ms
(the same amount of milliseconds it takes to fade out)
setTimeout(function(){ div.style.display = "none"; }, 600);
}
}
</script>
Try it Yourself »
Tip: Also check out Notes.