How do I make a CSS triangle with smooth edges?

Question

I have a triangle (JSFiddle) using this CSS:

.triangle {
    width: 0;
    height: 0;
    border-top: 0;
    border-bottom: 30px solid #666699;
    border-le         


        

Answer 1

For Firefox you can add -moz-transform: scale(.9999); to make smooth edges. In your case:

.triangle {
    width: 0;
    height: 0;
    border-top: 0;
    border-bottom: 30px solid #666699;
    border-left: 20px solid transparent; 
    border-right: 20px solid transparent;
    -moz-transform: scale(.9999);
}

Will do the trick.

Answer 2

For me, using dashed for the transparent borders worked for most browsers that don't automatically smooth them and rotating 360 degrees worked for old Webkit:

.triangle {
    width: 0;
    height: 0;
    border-top: 0;
    border-bottom: 30px solid #666699;
    border-left: 20px dashed transparent; 
    border-right: 20px dashed transparent;
    -webkit-transform: rotate(360deg);
}