Run results for: TextDecoder 'ascii' vs String.fromCharCode

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_5_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/137.0.7151.107 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 137

Operating system: iOS 18.5.0

Device Platform: Mobile

Date tested: one year ago

TextDecoder

5.1M/s

String.fromCharCode

4.9M/s

View exact numbers

Test name	Executions per second
✓ TextDecoder	5,057,200 Ops/sec
String.fromCharCode	4,925,823 Ops/sec

Script Preparation code:

var bytes = [84,104,105,115,32,105,115,32,97,32,115,97,109,112,108,101,32,112,97,114,97,103,114,97,112,104,46];
var bufferArray = new Uint16Array(bytes);
var decoder = new TextDecoder('ascii'); // default 'utf-8' or 'utf8'

Tests:

String.fromCharCode
String.fromCharCode.apply(null, bufferArray);
TextDecoder
decoder.decode(bufferArray);