I prefer to use another tool for gradients generation - EnjoyCSS.
It also allows to generate other CSS features like background, shadows, transitions etc.
White to transparent gradient generated with this tool:
background-image: -webkit-linear-gradient(-90deg, rgba(255,255,255,0) 0, rgba(255,255,255,1) 100%);
background-image: -moz-linear-gradient(180deg, rgba(255,255,255,0) 0, rgba(255,255,255,1) 100%);
background-image: linear-gradient(180deg, rgba(255,255,255,0) 0, rgba(255,255,255,1) 100%);
background-position: 50% 50%;
-webkit-background-origin: padding-box;
background-origin: padding-box;
-webkit-background-clip: border-box;
background-clip: border-box;
-webkit-background-size: auto auto;
background-size: auto auto;