garfild304,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.blok1 {
width: 100px;
background-color: #00C700;
float: left;
transition: height 1.2s ease-in-out;
}
</style>
<script>
document.addEventListener("DOMContentLoaded", function() {
setTimeout(resizeElement, 1000)
}, false);
function resizeElement() {
var maxHeight = 0;
[].filter.call(document.querySelectorAll(".blok1"), function(el) {
var elHeight = el.clientHeight;
elHeight > maxHeight && (maxHeight = elHeight);
return elHeight > 100
}).forEach(function(el) {
el.style.height = maxHeight + "px"
})
};
</script>
</head>
<body>
<div class="blok1" style="height: 300px">1</div>
<div class="blok1" style="height: 80px">2</div>
<div class="blok1" style="height: 150px">3</div>
<div class="blok1" style="height: 50px">4</div>
<div class="blok1" style="height: 200px">5</div>
</body>
</html>