How to Code an Expanding HTML5/CSS3 Search Input Field

A common user interface style for Apple and WordPress has been the expanding search field. Whenever a user clicks to focus, the field will expand wider, then contracts when the user de-focuses. This technique has become popular because it saves room on your page when the search isn’t being used. But it also highlights the search field when it is in use, which catches the user’s attention and lets them know the website is responding.

In this tutorial you’ll follow two different methods for building an expanding search field. The first is using basic CSS3 transitions which are only supported in newer web browsers. This works great for simple designs, but there is no way to check if the user has entered data strictly via CSS. In the second field you will use JavaScript to expand, and then only shrink back if the user hasn’t entered any text.