Auto expand a textarea using jQuery

Question

How can I make a textarea automatically expand using jQuery?

I have a textbox for explaining the agenda of the meeting, so I want to expand that textbox when my agenda's text keep growing that textbox area.

Answer 1

People seem to have very over worked solutions...

This is how I do it:

  $('textarea').keyup(function()
  {
    var 
    $this  = $(this),
    height = parseInt($this.css('line-height'),     10),
    padTop = parseInt($this.css('padding-top'),     10),
    padBot = parseInt($this.css('padding-bottom'),  10);

    $this.height(0);

    var 
    scroll = $this.prop('scrollHeight'),
    lines  = (scroll  - padTop - padBot) / height;

    $this.height(height * lines);
  });

This will work with long lines, as well as line breaks.. grows and shrinks..

Answer 2

function autosize(textarea) {
    $(textarea).height(1); // temporarily shrink textarea so that scrollHeight returns content height when content does not fill textarea
    $(textarea).height($(textarea).prop("scrollHeight"));
}

$(document).ready(function () {
    $(document).on("input", "textarea", function() {
        autosize(this);
    });
    $("textarea").each(function () {
        autosize(this);
    });
});

(This will not work in Internet Explorer 9 or older as it makes use of the input event)

Answer 3

You can try this one

$('#content').on('change keyup keydown paste cut', 'textarea', function () {
        $(this).height(0).height(this.scrollHeight);
    }).find('textarea').change();

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="content">
  <textarea>How about it</textarea><br />
  <textarea rows="5">111111
222222
333333
444444
555555
666666</textarea>
</div>

Answer 4

I just built this function to expand textareas on pageload. Just change each to keyup and it will occur when the textarea is typed in.

// On page-load, auto-expand textareas to be tall enough to contain initial content
$('textarea').each(function(){
    var pad = parseInt($(this).css('padding-top'));
    if ($.browser.mozilla) 
        $(this).height(1);
    var contentHeight = this.scrollHeight;
    if (!$.browser.mozilla) 
        contentHeight -= pad * 2;
    if (contentHeight > $(this).height()) 
        $(this).height(contentHeight);
});

Tested in Chrome, IE9 and Firefox. Unfortunately Firefox has this bug which returns the incorrect value for scrollHeight, so the above code contains a (hacky) workaround for it.

Answer 5

Old question but you could do something like this:

html:

<textarea class="text-area" rows="1"></textarea>

jquery:

var baseH; // base scroll height

$('body')
    .one('focus.textarea', '.text-area', function(e) {
        baseH = this.scrollHeight;
    })
    .on('input.textarea', '.text-area', function(e) {
        if(baseH < this.scrollHeight) {
            $(this).height(0).height(this.scrollHeight);
        }
        else {
            $(this).height(0).height(baseH);
        }
    });

This way the auto resize will apply to any textarea with the class "text-area". Also shrinks when text is removed.

jsfiddle:

https://jsfiddle.net/rotaercz/46rhcqyn/

Answer 6

I have tried lots and this one is great. ^{Link is dead. Newer version is available here. See below for old version.}
You can try by pressing and hold enter key in textarea. Compare the effect with the other auto expanding textarea plugin....

edit based on comment

$(function() {
   $('#txtMeetingAgenda').autogrow();
});

note: you should include the needed js files...

To prevent the scrollbar in the textarea from flashing on & off during expansion/contraction, you can set the overflow to hidden as well:

$('#textMeetingAgenda').css('overflow', 'hidden').autogrow()

---

Update:

The link above is broken. But you can still get the javascript files here.