Run results for: JavaScript spread operator vs Object.assign performance

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36 Edg/139.0.0.0

Browser: Chrome 139

Operating system: Windows

Device Platform: Desktop

Date tested: 11 months ago

Using Object.assign

25.6M/s

Using the spread operator

22.8M/s

View exact numbers

Test name	Executions per second
✓ Using Object.assign	25,632,740 Ops/sec
Using the spread operator	22,802,834 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);