Benchmark: JavaScript spread operator vs Object.assign vs direct member access performance

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);
direct member access
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { sampleData: firstObject['sampleData'], moreData: secondObject['moreData'] };

Rendered benchmark preparation results:

Previous results

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36 Edg/133.0.0.0

Browser/OS: Chrome 133 on Windows

direct member access

143.8M/s

Using Object.assign

40.2M/s

Using the spread operator

37.5M/s

View exact numbers

JavaScript spread operator vs Object.assign vs direct member access performance (version: 1)