.append VS .html VS .innerHTML performance

Question

This site's run a test between the 3 different methods and it seems .html is the fastest, followed by .append. followed by .innerHTML. Can someone explain to me the reasons why?

Here's the site which does the comparison among the three methods.

I have read this this SO question which is related but I don't really understand the given answer, and the question didn't really elaborate much regarding .innerHtml.

I don't understand the following part:

A temporary element is created, let's call it x. x's innerHTML is set to the string of HTML that you've passed. Then jQuery will transfer each of the produced nodes (that is, x's childNodes) over to a newly created document fragment, which it will then cache for next time. It will then return the fragment's childNodes as a fresh DOM collection. Note that it's actually a lot more complicated than that, as jQuery does a bunch of cross-browser checks and various other optimisations. E.g. if you pass just <div></div> to jQuery(), jQuery will take a shortcut and simply do document.createElement('div').

Can someone simplify this?

Answer 1

All three are slow to me. Modifying the dom on each iteration is slow.

http://jsperf.com/jquery-append-vs-html-list-performance/24

I just added a new test in there:

var html = []; for (var i = 0; i < len; i++) {   html.push('<div>Test ' + i + '</div>'); }  document.getElementById('list').innerHTML = html.join(''); 

This is much faster again. :)

My method in Firefox does 26k Ops/sec vs 1,000, 10,000, and 13

Answer 2

That benchmark is worthless. innerHTML is always faster than DOM manipulation.

jQuery seems faster because it prepares a string with all the HTML first while the others do one operation each iteration. Also note that jQuery.html() uses innerHTML whenever it can.

jQuery from benchmark

var html = ''; for (var i = 0; i < len; i++) {   html += '<div>Test ' + i + '</div>'; }  $('#list').html(html); 

innerHTML from benchmark

var list = document.getElementById('list'); for (var i = 0; i < len; i++) {   list.innerHTML = list.innerHTML + '<div>Test ' + i + '</div>'; } 

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The test for innerHTML would be a lot faster if it was written like:

var list = document.getElementById('list'); var html = '';  for (var i = 0; i < len; i++) {     html += '<div>Test ' + i + '</div>'; }  list.innerHTML = html; 

http://jsben.ch/#/yDvKH