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

For concat

Benchmark created by Renato Rodrigues on September 20, 2012

Test runner

Ready to run.

Test Ops/sec

concat

Testing in
Test	Ops/sec
concat	`var s = ''; for (i=100;i>=0;i--){ s+=i; } console.log(s);`	ready
join	`var s = []; for (i=100;i>=0;i--){ s.push(i.toString()); } console.log(s.join(''));`	ready
join plus	`var s = []; for (i=0;i>=100;i++){ s.push(i.toString()); } console.log(s.join(''));`	ready

var s = '';
for (i=100;i>=0;i--){
    s+=i;
}
console.log(s);

ready

join

var s = [];
for (i=100;i>=0;i--){
    s.push(i.toString());
}
console.log(s.join(''));

ready

join plus

var s = [];
for (i=0;i>=100;i++){
    s.push(i.toString());
}
console.log(s.join(''));

ready

Revisions

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

Revision 1: published by Renato Rodrigues on September 20, 2012