I would call five out of 13 "A lot", especially when the very first one listed isn't an attribute.

defaultValue, selectionStart, selectionEnd, selectionDirection, and indeterminate are NOT HTML attributes. They're properties of the HTMLInputElement Object.

Though yes, if you go into the WhatWG's garbage they do love using the word attribute for things that aren't attributes. Just more proof they were never qualified to make 4 Strict's successor in the first place much less open their trap about the DOM.

Try doing HTMLInputElement.getAttribute("defaultValue") You get NULL, whilst HTMLInputElement.defaultValue will return the value declared in value="" in the markup irregardless of the current HTMLInputElement.value.

There is no:

<input defaultValue="5">

Just as there's no such thing as a className or classList attribute. "class" is the attribute, className and classList are properties.

That difference is pretty damned important.