Run results for: getElementById vs. querySelector

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36

Browser: Chrome 73

Operating system: Windows

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
getElementById	4243543.5 Ops/sec
querySelector	2284121.0 Ops/sec
getElementById or querySelector	1786126.8 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");