there’s no way to create it using only HTML and CSS

Expanding Text Areas Made Elegant · An A List Apart Article

Submitted by michael on Thu, 01/01/2015 - 16:16

An expanding text area is a multi-line text input field that expands in height to fit
its contents. Commonly found in both desktop and mobile applications, such as the SMS
composition field on the iPhone, it’s a good choice when you don’t know how much text the
user will write and you want to keep the layout compact; as such, it’s especially useful on
interfaces targeted at smartphones. Yet despite the ubiquity of this control, there’s no way
to create it using only HTML and CSS, and most JavaScript solutions have suffered from