Editing getElementById and querySelector VS named element This edit will create a new revision. Your details (optional) Name Email (won’t be displayed; might be used for Gravatar) URL Test case details Title * Published (uncheck if you want to fiddle around before making the page public) Description (in case you feel further explanation is needed)(Markdown syntax is allowed) This test shows the performance difference between getting the reference to a DOM element by calling getElementById, querySelector and accessing it via the named element of window. The test only uses one HTML element with the id as the standard expects to only have one unique element with that ID in the DOM. Other than that the created object "node" will contain a collection if we use querySelector or the named element. Are you a spammer? (just answer the question) Preparation code Preparation code HTML (this will be inserted in the <body> of a valid HTML5 document in standards mode) (useful when testing DOM operations or including libraries) <div id="testid"></div> Include JavaScript libraries as follows: <script src="//cdn.ext/library.js"></script> Define setup for all tests (variables, functions, arrays or other objects that will be used in the tests) (runs before each clocked test loop, outside of the timed code region) (e.g. define local test variables, reset global variables, clear canvas, etc.) (see FAQ) Define teardown for all tests (runs after each clocked test loop, outside of the timed code region) (see FAQ) Code snippets to compare Test 1 Title Async (check if this is an asynchronous test) Code node = document.getElementById('testid'); Test 2 Title Async (check if this is an asynchronous test) Code node = document.querySelector('#testid'); Test 3 Title Async (check if this is an asynchronous test) Code node = window.testid;