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/131.0.0.0 Safari/537.36 Edg/131.0.0.0

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Using the spread operator

41.8M/s

Using Object.assign

13.7M/s

View exact numbers

Test name	Executions per second
✓ Using the spread operator	41,809,204 Ops/sec
Using Object.assign	13,721,582 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);