Run results for: fromEvent vs addEventListener

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.2 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 6 months ago

fromEvent

10K/s

addEventListener

4K/s

View exact numbers

Test name	Executions per second
✓ fromEvent	9,705 Ops/sec
addEventListener	4,189 Ops/sec

HTML Preparation code:

<script src='https://unpkg.com/rxjs@^7/dist/bundles/rxjs.umd.min.js'></script>

Tests:

fromEvent
let { fromEvent, throttleTime, map, scan } = rxjs; fromEvent(document, 'click') .pipe( throttleTime(1000), map((event) => event.clientX), scan((count, clientX) => count + clientX, 0) ) .subscribe((count) => console.log(count));
addEventListener
let count = 0; const rate = 1000; let lastClick = Date.now() - rate; document.addEventListener('click', (event) => { if (Date.now() - lastClick >= rate) { count += event.clientX; console.log(count); lastClick = Date.now(); } });