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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:129.0) Gecko/20100101 Firefox/129.0

Browser: Firefox 129

Operating system: Windows

Device Platform: Desktop

Date tested: 3 months ago

Test name	Executions per second
Using the spread operator	1142634.1 Ops/sec
Using Object.assign	3065537.2 Ops/sec

Tests:

Using the spread operator
const objectToCopy = { sampleString1: 'Hello world', sampleNumber1: 123456789, sampleArray1: ['hello', 'world', 'how', 'are', 'you'], sampleString2: 'Hello world', sampleNumber2: 123456789, sampleArray2: ['hello', 'world', 'how', 'are', 'you'], sampleString3: 'Hello world', sampleNumber3: 123456789, sampleArray3: ['hello', 'world', 'how', 'are', 'you'], sampleString4: 'Hello world', sampleNumber4: 123456789, sampleArray4: ['hello', 'world', 'how', 'are', 'you'], sampleString5: 'Hello world', sampleNumber5: 123456789, sampleArray5: ['hello', 'world', 'how', 'are', 'you'], sampleString6: 'Hello world', sampleNumber6: 123456789, sampleArray6: ['hello', 'world', 'how', 'are', 'you'], sampleString7: 'Hello world', sampleNumber7: 123456789, sampleArray7: ['hello', 'world', 'how', 'are', 'you'], sampleString8: 'Hello world', sampleNumber8: 123456789, sampleArray8: ['hello', 'world', 'how', 'are', 'you'], sampleString9: 'Hello world', sampleNumber9: 123456789, sampleArray9: ['hello', 'world', 'how', 'are', 'you'], sampleString10: 'Hello world', sampleNumber10: 123456789, sampleArray10: ['hello', 'world', 'how', 'are', 'you'], } const finalObject = { ...objectToCopy, };
Using Object.assign
const objectToCopy = { sampleString1: 'Hello world', sampleNumber1: 123456789, sampleArray1: ['hello', 'world', 'how', 'are', 'you'], sampleString2: 'Hello world', sampleNumber2: 123456789, sampleArray2: ['hello', 'world', 'how', 'are', 'you'], sampleString3: 'Hello world', sampleNumber3: 123456789, sampleArray3: ['hello', 'world', 'how', 'are', 'you'], sampleString4: 'Hello world', sampleNumber4: 123456789, sampleArray4: ['hello', 'world', 'how', 'are', 'you'], sampleString5: 'Hello world', sampleNumber5: 123456789, sampleArray5: ['hello', 'world', 'how', 'are', 'you'], sampleString6: 'Hello world', sampleNumber6: 123456789, sampleArray6: ['hello', 'world', 'how', 'are', 'you'], sampleString7: 'Hello world', sampleNumber7: 123456789, sampleArray7: ['hello', 'world', 'how', 'are', 'you'], sampleString8: 'Hello world', sampleNumber8: 123456789, sampleArray8: ['hello', 'world', 'how', 'are', 'you'], sampleString9: 'Hello world', sampleNumber9: 123456789, sampleArray9: ['hello', 'world', 'how', 'are', 'you'], sampleString10: 'Hello world', sampleNumber10: 123456789, sampleArray10: ['hello', 'world', 'how', 'are', 'you'], } const finalObject = Object.assign({}, objectToCopy);

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

Using the spread operator

Using Object.assign