See adeneo's answer, but don't forget encodeURIComponent
!
a.href = 'data:application/csv;charset=utf-8,' + encodeURIComponent(csvString);
Also, I needed to do "\r\n" not just "\n" for the row delimiter.
var csvString = csvRows.join("\r\n");
Revised fiddle: http://jsfiddle.net/7Q3c6/