Run results for: char index vs charAt() vs slice() vs at() - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:101.0) Gecko/20100101 Firefox/101.0

Browser: Firefox 101

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
character index	115402600.0 Ops/sec
charAt()	106457100.0 Ops/sec
slice()	31568140.0 Ops/sec
at()	63809680.0 Ops/sec

Website performance monitoring

Script Preparation code:

var str = 'foo bar baz';
var noop = Function.prototype;

Tests:

character index
if (str[0] === 'f') noop();
charAt()
if (str.charAt(0) === 'f') noop();
slice()
if (str.slice(0, 1) === 'f') noop();
at()
if (str.at(0) === 'f') noop();