Benchmark: .endsWith vs .charAt for single character

HTML Preparation code:

<div></div>

Script Preparation code:

var data = window.data = [];
const possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
var TOTAL_STRINGS = window.TOTAL_STRINGS = 100000;

function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

function makeRandomString(len) {
  var text = "";
  for( var i=0; i < len; i++ ) {
    text += possible.charAt(getRandomInt(possible.length));
  }
  return text;
}

while (data.length < TOTAL_STRINGS) {
  data.push(makeRandomString(getRandomInt(20)));
}

Tests:

startsWith
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var regex = window.regex; while (x < TOTAL_STRINGS) { const str = data[x]; str.endsWith("9"); x += 1; }
.charAt
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.match; while (x < TOTAL_STRINGS) { const str = data[x]; str.charAt(-1) === '9'; x += 1; }

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

.charAt

5K/s

startsWith

2K/s

Fastest: .charAt (2.4x faster)

View exact numbers

✓ .charAt: 4,508 ops/sec
• startsWith: 1,904 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith
.charAt

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Browser/OS: Chrome 138 on Windows

View result in a separate tab

.charAt

12K/s

startsWith

2K/s

View exact numbers

Test name	Executions per second
✓ .charAt	11,903 Ops/sec
startsWith	1,904 Ops/sec

.endsWith vs .charAt for single character (version: 0)

Testing some things

Comparing performance of: `startsWith vs .charAt`

Created: 6 years ago by: Guest

Go to the latest result

startsWith

.charAt

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

.endsWith vs .charAt for single character (version: 0)

Testing some things

Comparing performance of: startsWith vs .charAt

Created: 6 years ago by: Guest

Go to the latest result

startsWith

.charAt

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `startsWith vs .charAt`