<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
</head>
<body>
<svg width="150" height="150">
<defs>
<filter id="filter" x="0" y="0">
<feGaussianBlur in="SourceGraphic" stdDeviation="20" />
</filter>
</defs>
<rect width="110" height="110" stroke="green" stroke-width="5" fill="lightblue" filter="url(#filter)" />
Sorry, your browser doesn't support inline SVG.
</svg>
</body>
</html>