Run results for: Object.entries vs Object.keys vs for..in

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Browser: Chrome 138

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

for..in

16K/s

Object.entries

15K/s

Object.keys

14K/s

View exact numbers

Test name	Executions per second
✓ for..in	16,362 Ops/sec
Object.entries	14,994 Ops/sec
Object.keys	14,348 Ops/sec

Script Preparation code:

var obj = {
	a: 1,
    b: 2,
	c: 3,
	d: 4,
  	e: 7,
  	f: 3,
  	g: 14,
  	h: 1,
  	i: 88,
  	j: 0,
  	k: 5,
	0: 'a',
  	1: 'b',
  	str: 'long string',
	nested: {
    	nested: 0
    },
	hello: 55.5
};

Tests:

Object.entries
for (const [key, val] of Object.entries(obj)){ console.log(key, val); }
for..in
for (let key in obj) { console.log(key, obj[key]) }
Object.keys
for (let key of Object.keys(obj)) { console.log(key, obj[key]); }