Run results for: JavaScript spread operator vs object update performance

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 months ago

Using update

503.0M/s

Using Object.assign

33.6M/s

View exact numbers

Test name	Executions per second
✓ Using update	502,993,760 Ops/sec
Using Object.assign	33,597,628 Ops/sec

Tests:

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