User input and string manipulation are central to development, but many engineers and even popular libraries struggle with Unicode. And ECMAScript 5 doesn’t help, with many built-in string manipulation functions offering puzzling results. Security and the need for internationalization both throw these issues into stark relief. This talk highlights the many problems related to Unicode in JavaScript regular expressions, demonstrates how ES6 (aka. ECMAScript 2015) helps solve these issues, and explains how to polyfill in the mean time.