Forms

See Click for the click event.

On input

Execute when a user writes something in an input field.

The oninput is useful if you want to detect when the contents of a textarea, input:text, input:password or input:search element have changed, because the onchange event on these elements fires when the element loses focus, not immediately after the modification. source

el.oninput = myFunction()

Or

<input type="text" oninput="myFunction()">

On change

Execute when a user changes the value of an input field. This is more precise as I think it doesn’t fire if you choose the same option in the droplist as before and it only fires when you’ve click a droplist option or change focus away from a text field and not on every interaction to click or type.

onchange occurs when the selection, the checked state or the contents of an element have changed. In some cases, it only occurs when the element loses the focus. The onchange attribute can be used with: <input>, <select>, and <textarea>. source

el.onchange = myFunction()

Or

<input type="text" onchange="myFunction()">