Run results for: Classnames vs CLSX vs Alternatives 2025

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0

Browser: Firefox 147

Operating system: Windows

Device Platform: Desktop

Date tested: 4 months ago

Test name	Executions per second
classnames	2283445.0 Ops/sec
clsx	3116965.0 Ops/sec
Array based	2770370.0 Ops/sec
String based (return struct)	3692062.8 Ops/sec
String based (if-else struct)	3600311.5 Ops/sec
Entries, filter, map, join	3048390.2 Ops/sec

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/classnames/2.5.1/index.min.js'></script>
<script src='https://unpkg.com/clsx@2.1.1/dist/clsx.min.js'></script>

Script Preparation code:

var str = 'style';
var obj = {
 	 'style-2': true,
  	 'style-3': false,
 	 'style-4': true,
}
var arr = ['style-5', 'style-6']

Tests:

classnames
let result = window.classNames(str, obj, arr, 'test classname')
clsx
let result = window.clsx(str, obj, arr, 'test classname')
Array based
function ts(...args){ let template = []; args.forEach(arg => { if (typeof arg === 'string') { template.push(arg); return; } if (arg.join) { template = [...template, ...arg]; return; } let entries = Object.entries(arg); if (entries.length) { entries.forEach(entry => { if(entry[1]) template.push(entry[0]) }) } }) return template.join(' '); } let result = ts(str, obj, arr, 'test classname')
String based (return struct)
function ts(...args){ let template = ''; args.forEach(arg => { if (typeof arg === 'string') { template += ' '+arg; return; } if (arg.join) { arg.forEach((e) => { template += ' ' + e; }) return; } let entries = Object.entries(arg); if (entries.length) { entries.forEach(entry => { if(entry[1]) template += ' ' + entry[0] }) } }) return template; } let result = ts(str, obj, arr, 'test classname')
String based (if-else struct)
function ts(...args){ let template = ''; args.forEach(arg => { if (typeof arg === 'string') { template += ' '+arg; } else if (arg.join) { arg.forEach((e) => { template += ' ' + e; }) } else { let entries = Object.entries(arg); if (entries.length) { entries.forEach(entry => { if(entry[1]) template += ' ' + entry[0] }) } } }) return template; } let result = ts(str, obj, arr, 'test classname')
Entries, filter, map, join
let objStyle = Object.entries(obj).filter((style)=>style[1]).map(style => style[0]).join(' '); let arrComb = arr.join(' ') let result = `${str} ${objStyle} ${arrComb} test classname`

Run results for: Classnames vs CLSX vs Alternatives 2025

Compare CLSX vs Classnames vs an own implementation of creating a template string

classnames

clsx

Array based

String based (return struct)

String based (if-else struct)

Entries, filter, map, join