Run results for: iframe vs window (new)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36

Browser: Chrome 84

Operating system: Mac OS X 10.15.4

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Iframe string	15.4 Ops/sec
window string	14.7 Ops/sec

Script Preparation code:

var iframe = document.createElement("iframe");
iframe.src = "about:blank";
document.documentElement.appendChild(iframe);
var _window = iframe.contentWindow;

Tests:

Iframe string
for(var i = 0; i < 200000; i++) { new _window.String("a random string").split(""); }
window string
for(var i = 0; i < 200000; i++) { new String("a random string").split(""); }

Run results for: iframe vs window (new)

Iframe string

window string