Best way to track onchange as-you-type in input type="text"?

Solution 1:

These days listen for oninput. It feels like onchange without the need to lose focus on the element. It is HTML5.

It’s supported by everyone (even mobile), except IE8 and below. For IE add onpropertychange. I use it like this:

const source = document.getElementById('source');
const result = document.getElementById('result');

const inputHandler = function(e) {
  result.innerHTML = e.target.value;
}

source.addEventListener('input', inputHandler);
source.addEventListener('propertychange', inputHandler); // for IE8
// Firefox/Edge18-/IE9+ don’t fire on <select><option>
// source.addEventListener('change', inputHandler); 

<input id="source">
<div id="result"></div>

Solution 2:

Update:

See Another answer (2015).

Original 2009 Answer:

So, you want the onchange event to fire on keydown, blur, and paste? That's magic.

If you want to track changes as they type, use "onkeydown". If you need to trap paste operations with the mouse, use "onpaste" (IE, FF3) and "oninput" (FF, Opera, Chrome, Safari¹).

¹_{Broken for <textarea> on Safari. Use textInput instead}

Solution 3:

Below code works fine for me with Jquery 1.8.3

HTML : <input type="text" id="myId" />

Javascript/JQuery:

$("#myId").on('change keydown paste input', function(){
      doSomething();
});

Solution 4:

Javascript is unpredictable and funny here.

• onchange occurs only when you blur the textbox
• onkeyup & onkeypress doesn't always occur on text change
• onkeydown occurs on text change (but cannot track cut & paste with mouse click)
• onpaste & oncut occurs with keypress and even with the mouse right click.

So, to track the change in textbox, we need onkeydown, oncut and onpaste. In the callback of these event, if you check the value of the textbox then you don't get the updated value as the value is changed after the callback. So a solution for this is to set a timeout function with a timeout of 50 mili-seconds (or may be less) to track the change.

This is a dirty hack but this is the only way, as I researched.

Here is an example. http://jsfiddle.net/2BfGC/12/