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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:124.0) Gecko/20100101 Firefox/124.0

Browser: Firefox 124

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Using Object.assign

31.4M/s

Using the spread operator

15.4M/s

View exact numbers

Test name	Executions per second
✓ Using Object.assign	31,385,616 Ops/sec
Using the spread operator	15,382,991 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);