scroll down animation code example

Example 1: smooth scroll css

html {
  scroll-behavior: smooth;
}

/* No support in IE, or Safari
You can use this JS polyfill for those */
http://iamdustan.com/smoothscroll/

Example 2: aos js

CSS
<link href="https://unpkg.com/[email protected]/dist/aos.css" rel="stylesheet">

JS
<script src="https://unpkg.com/[email protected]/dist/aos.js"></script>

INITIALIZE AOS:
<script>
  AOS.init();
</script>

Example 3: smooth scrolll to id js

// handle links with @href started with '#' only
$(document).on('click', 'a[href^="#"]', function(e) {
    // target element id
    var id = $(this).attr('href');

    // target element
    var $id = $(id);
    if ($id.length === 0) {
        return;
    }

    // prevent standard hash navigation (avoid blinking in IE)
    e.preventDefault();

    // top position relative to the document
    var pos = $id.offset().top;

    // animated top scrolling
    $('body, html').animate({scrollTop: pos});
});

Example 4: aos animate

<script src="https://unpkg.com/[email protected]/dist/aos.js"></script>