How to Get a Textarea to Stretch to Fit Its Content Without Using PHP or JavaScript

Is there a way to get a textarea to stretch to fit its content without using PHP or JavaScript?

Not really. This is normally done using javascript.

there is a good discussion of ways of doing this here...

Autosizing textarea using Prototype

Textarea to resize based on content length

You can check the content's height by setting to 1px and then reading the scrollHeight property:

function textAreaAdjust(element) {
  element.style.height = "1px";
  element.style.height = (25+element.scrollHeight)+"px";
}

<textarea onkeyup="textAreaAdjust(this)" style="overflow:hidden"></textarea>

Creating a textarea with auto-resize

This works for me (Firefox 3.6/4.0 and Chrome 10/11):

var observe;if (window.attachEvent) {    observe = function (element, event, handler) {        element.attachEvent('on'+event, handler);    };}else {    observe = function (element, event, handler) {        element.addEventListener(event, handler, false);    };}function init () {    var text = document.getElementById('text');    function resize () {        text.style.height = 'auto';        text.style.height = text.scrollHeight+'px';    }    /* 0-timeout to get the already changed text */    function delayedResize () {        window.setTimeout(resize, 0);    }    observe(text, 'change',  resize);    observe(text, 'cut',     delayedResize);    observe(text, 'paste',   delayedResize);    observe(text, 'drop',    delayedResize);    observe(text, 'keydown', delayedResize);
    text.focus();    text.select();    resize();}

textarea {    border: 0 none white;    overflow: hidden;    padding: 0;    outline: none;    background-color: #D0D0D0;}

<body onload="init();"><textarea rows="1" style="height:1em;" id="text"></textarea></body>

How to autosize a textarea using Prototype?

Facebook does it, when you write on people's walls, but only resizes vertically.

Horizontal resize strikes me as being a mess, due to word-wrap, long lines, and so on, but vertical resize seems to be pretty safe and nice.

None of the Facebook-using-newbies I know have ever mentioned anything about it or been confused. I'd use this as anecdotal evidence to say 'go ahead, implement it'.

Some JavaScript code to do it, using Prototype (because that's what I'm familiar with):

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
  "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <script src="http://www.google.com/jsapi"></script>
        <script language="javascript">
            google.load('prototype', '1.6.0.2');
        </script>
    </head>

    <body>
        <textarea id="text-area" rows="1" cols="50"></textarea>

        <script type="text/javascript" language="javascript">
            resizeIt = function() {
              var str = $('text-area').value;
              var cols = $('text-area').cols;

              var linecount = 0;
              $A(str.split("\n")).each( function(l) {
                  linecount += Math.ceil( l.length / cols ); // Take into account long lines
              })
              $('text-area').rows = linecount + 1;
            };

            // You could attach to keyUp, etc. if keydown doesn't work
            Event.observe('text-area', 'keydown', resizeIt );

            resizeIt(); //Initial on load
        </script>
    </body>
</html>

PS: Obviously this JavaScript code is very naive and not well tested, and you probably don't want to use it on textboxes with novels in them, but you get the general idea.

It is possible to expand a textarea only with CSS?

Instead of textarea , you can use div with contentEditable attribute:

div {  display: inline-block;  border: solid 1px #000;  min-height: 200px;  width: 300px;}

<div contentEditable="true"></div>

Textarea Auto height

~~It can be achieved using JS. Here is a 'one-line' solution using elastic.js:~~

$('#note').elastic();

Updated: Seems like elastic.js is not there anymore, but if you are looking for an external library, I can recommend autosize.js by Jack Moore. This is the working example:

autosize(document.getElementById("note"));

textarea#note { width:100%; box-sizing:border-box; direction:rtl; display:block; max-width:100%; line-height:1.5; padding:15px 15px 30px; border-radius:3px; border:1px solid #F7E98D; font:13px Tahoma, cursive; transition:box-shadow 0.5s ease; box-shadow:0 4px 6px rgba(0,0,0,0.1); font-smoothing:subpixel-antialiased; background:linear-gradient(#F9EFAF, #F7E98D); background:-o-linear-gradient(#F9EFAF, #F7E98D); background:-ms-linear-gradient(#F9EFAF, #F7E98D); background:-moz-linear-gradient(#F9EFAF, #F7E98D); background:-webkit-linear-gradient(#F9EFAF, #F7E98D);}

<script src="https://rawgit.com/jackmoore/autosize/master/dist/autosize.min.js"></script><textarea id="note">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi.</textarea>