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

Run details:

User agent: Mozilla/5.0 (X11; CrOS x86_64 14541.0.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser: Chrome 130

Operating system: Chrome OS 14541.0.0

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Using the spread operator

35.9M/s

Using Object.assign

1.6M/s

View exact numbers

Test name	Executions per second
✓ Using the spread operator	35,921,756 Ops/sec
Using Object.assign	1,616,238 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 a1 = Object.entries(firstObject) const a2 = Object.entries(secondObject) const finalObject = Object.fromEntries(a1.concat(a2));