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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:121.0) Gecko/20100101 Firefox/121.0

Browser: Firefox 121

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Using Object.assign

23.9M/s

Using the spread operator

12.2M/s

View exact numbers

Test name	Executions per second
✓ Using Object.assign	23,865,202 Ops/sec
Using the spread operator	12,184,395 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);