Count bytes in textarea using javascript

Question

I need to count how long in bytes a textarea is when UTF8 encoded using javascript. Any idea how I would do this?

thanks!

Answer 1

encodeURIComponent(text).replace(/%[A-F\d]{2}/g, 'U').length

Answer 2

Combining various answers, the following method should be fast and accurate, and avoids issues with invalid surrogate pairs that can cause errors in encodeURIComponent():

function getUTF8Length(s) {
  var len = 0;
  for (var i = 0; i < s.length; i++) {
    var code = s.charCodeAt(i);
    if (code <= 0x7f) {
      len += 1;
    } else if (code <= 0x7ff) {
      len += 2;
    } else if (code >= 0xd800 && code <= 0xdfff) {
      // Surrogate pair: These take 4 bytes in UTF-8 and 2 chars in UCS-2
      // (Assume next char is the other [valid] half and just skip it)
      len += 4; i++;
    } else if (code < 0xffff) {
      len += 3;
    } else {
      len += 4;
    }
  }
  return len;
}

Answer 3

encodeURI(text).split(/%..|./).length - 1

Answer 4

set meta UTF-8 just & it's OK!

<meta charset="UTF-8">
<meta http-equiv="content-type" content="text/html;charset=utf-8">

and js:

if($mytext.length > 10){
 // its okkk :)
}