jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.

jsperf.com URLs are mirrored at the same path, e.g:

https://jsperf.com/negative-modulo/2

Can be accessed at:

https://jsperf.app/negative-modulo/2

String vs '' + vs + '' (v2)

Revision 2 of this benchmark created by Labi Kyo on December 3, 2012

Preparation HTML

<script>
  var number_string = '1234567890',
      result;
</script>

Test runner

Ready to run.

Testing in
Test		Ops/sec
String	`result = String(number_string);`	ready
new String	`result = new String(number_string);`	ready
'' + str	`result = '' + number_string;`	ready
str + ''	`result = number_string + '';`	ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

Revision 1: published on September 30, 2010
Revision 2: published by Labi Kyo on December 3, 2012