You can add the .fade and .show classes to animate alerts when dismissing them.
Example:
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css" integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk" crossorigin="anonymous">
<!-- JavaScript Plugins -->
<!-- jQuery first, then Popper.js,
then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js" integrity="sha384-OgVRvuATP1z7JjHLkuOU7Xw704+h835Lr+6QL9UvYjZE3Ipu6Tp75j7Bh/kR0JKI" crossorigin="anonymous"></script>
<title>
How to Remove extra right margin
when using alert-dismissible?
</title>
</head>
<body>
<div class="container">
<a class="navbar-brand text-success" href="#">
BAJARANGI SOFT
</a>
<div class="alert alert-warning alert-dismissible fade show" role="alert">
<b>Hello Everyone!</b>
click on 'x' symbol to close
<button type="button" class="close" data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
</div>
</body>
</html>
$('.alert').alert()
button type="button" class="close"
data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css" integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk" crossorigin="anonymous">
<!-- JavaScript Plugins -->
<!-- jQuery first, then Popper.js,
then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js" integrity="sha384-OgVRvuATP1z7JjHLkuOU7Xw704+h835Lr+6QL9UvYjZE3Ipu6Tp75j7Bh/kR0JKI" crossorigin="anonymous"></script>
<style type="text/css">
.fade {
-webkit-transition-duration: 7s;
/* Safari */
transition-duration: 7s;
}
</style>
</head>
<body>
<div class="container">
<a class="navbar-brand text-success"
href="#">
BAJARANGI SOFT
</a>
<h2>
Alert dismiss using
javascript trigger
</h2>
<div class="alert alert-warning fade show">
<b>Hello Everyone!</b>
click on 'x' symbol to close
</div>
</div>
<!-- JavaScript trigger-->
<script>
$(document).ready(function () {
$(".alert").alert('close');
});
</script>
</body>
</html>
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css" integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk" crossorigin="anonymous">
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js,
then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js" integrity="sha384-OgVRvuATP1z7JjHLkuOU7Xw704+h835Lr+6QL9UvYjZE3Ipu6Tp75j7Bh/kR0JKI" crossorigin="anonymous"></script>
<title>
Remove extra right margin
using alert-dismissible
</title>
<style type="text/css">
.alert-dismissible {
margin-right: 100px;
/* Reset pixel value */
padding-right: 0px;
}
</style>
</head>
<body>
<div class="container">
<a class="navbar-brand text-success" href="#">
BAJARANGI SOFT
</a>
<div class="alert alert-warning alert-dismissible
fade show" role="alert">
<b>Hello Everyone!</b>
click on 'x' symbol to close
<button type="button" class="close"
data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
</div>
</body>
</html>