Reply To: how to fix the height of div same browser height

[Hornebom]

try this one or check this pen

<div id="left"></div>

* {margin:0;padding:0;}
#left {
  width: 20%;
  min-height: 100%;
  height: auto !important;
  height: 100%;
  overflow: hidden !important;
  background:red; /* just to see it */
}
html, body {
  height:100%;
}