Run results for: JavaScript spread operator vs Object.assign performance to merge into new object

Run details:

User agent: Mozilla/5.0 (Linux; Android 11; SAMSUNG SM-A705FN) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/23.0 Chrome/115.0.0.0 Mobile Safari/537.36

Browser: Chrome Mobile 115

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Using Object.assign

2.8M/s

Using the spread operator

1.1M/s

View exact numbers

Test name	Executions per second
✓ Using Object.assign	2,784,539 Ops/sec
Using the spread operator	1,140,696 Ops/sec

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({}, firstObject, secondObject);