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

in vs if

Benchmark created by Jason Mulligan on October 5, 2011

Preparation HTML

<script>
  var x = document.querySelector("body");
</script>

Test runner

Ready to run.

Testing in
Test		Ops/sec
in (invalid)	`if ("test" in x.dataset) { void(0); }`	ready
if (invalid)	`if (x.dataset["test"]) { void(0); }`	ready

Revisions

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

Revision 1: published by Jason Mulligan on October 5, 2011