Run results for: getElementById vs. querySelector

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:64.0) Gecko/20100101 Firefox/64.0

Browser: Firefox 64

Operating system: Ubuntu

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
getElementById	1402356.6 Ops/sec
querySelector	1450207.1 Ops/sec
getElementById or querySelector	792323.3 Ops/sec

HTML Preparation code:

<p id="foo">Foo</p>
<p id="bar">Bar</p>
<p id="baz">Baz</p>

Tests:

getElementById
var bar = document.getElementById("bar");
querySelector
var bar = document.querySelector("#bar");
getElementById or querySelector
var selector = "#bar", func = selector.match('^#[A-z0-9-]*$') ? "getElementById" : "querySelector", bar = document[func]("bar");