Resize text area to fit all text on load jquery

Try this

$("textarea").height( $("textarea")[0].scrollHeight );

DEMO

UPDATE

As a hack to make it work in older IE-s just add a really short delay before executing it

window.setTimeout( function() {
    $("textarea").height( $("textarea")[0].scrollHeight );
}, 1);​

DEMO

UPDATE FOR MULTIPLE TEXTAREAS

$("textarea").each(function(textarea) {
    $(this).height( $(this)[0].scrollHeight );
});