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

indexOf vs. charAt (v4)

Revision 4 of this benchmark created by Germán Toro del Valle on April 11, 2013

Preparation HTML

<script>
  var s = '+346666';
</script>

Test runner

Ready to run.

Testing in
Test		Ops/sec
indexOf	`if (s.indexOf("x") === 0) {}`	ready
charAt	`if (s.charAt(0) === "x") {}`	ready
array	`if (s[0] === "x") {}`	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 11, 2011
Revision 2: published by PlNG on February 21, 2012
Revision 4: published by Germán Toro del Valle on April 11, 2013
Revision 5: published by caitp on May 19, 2014
Revision 6: published on May 19, 2014