Run results for: querySelector vs querySelectorAll

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1.2 Safari/605.1.15

Browser: Safari 13

Operating system: Mac OS X 10.13.6

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
querySelector	169462.5 Ops/sec
querySelectorAll	933630.8 Ops/sec

HTML Preparation code:

<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>

Tests:

querySelector
for (var i = 0; i < 10; i++) { document.querySelector(".test:not(.read)", element => { element.classList.add("read") }) }
querySelectorAll
document.querySelectorAll(".test", elements => { elements.forEach(element => { element.classList.add("read") }) })