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

substring vs replace vs slice (v2)

Revision 2 of this benchmark created on January 15, 2026

Test runner

Ready to run.

Test Ops/sec

substring

Testing in
Test	Ops/sec
substring	`str = "http://google.com/" str.endsWith("/") ? str.substring(0, str.length - 1) : str`	ready
replace	`str = "http://google.com/" str.endsWith("/") ? str.replace(/\/+$/, "") : str`	ready
slice	`str = "http://google.com/" str.endsWith("/") ? str.slice(0, -1) : str`	ready

str = "http://google.com/"
str.endsWith("/") ? str.substring(0, str.length - 1) : str

ready

replace

str = "http://google.com/"
str.endsWith("/") ? str.replace(/\/+$/, "") : str

ready

slice

str = "http://google.com/"
str.endsWith("/") ? str.slice(0, -1) : str

ready

Revisions

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

Revision 1: published on January 15, 2026
Revision 2: published on January 15, 2026