Run results for: JavaScript fastest way to clone an object including JSON.parse and structuredClone methods

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:141.0) Gecko/20100101 Firefox/141.0

Browser: Firefox 141

Operating system: Linux

Device Platform: Desktop

Date tested: 8 months ago

Test name	Executions per second
Using the spread operator	10577992.0 Ops/sec
Using Object.assign	22762226.0 Ops/sec
Manually copying properties	71035976.0 Ops/sec
Create new object while copying	377939520.0 Ops/sec
Create new object from scratch	406770144.0 Ops/sec
StructuredClone	925358.5 Ops/sec
JSON	1161255.2 Ops/sec

Tests:

Using the spread operator
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = {...firstObject};
Using Object.assign
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = Object.assign({}, firstObject);
Manually copying properties
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; let finalObject = {}; finalObject.prop0 = firstObject.prop0; finalObject.prop1 = firstObject.prop1; finalObject.prop2 = firstObject.prop2; finalObject.prop3 = firstObject.prop3; finalObject.prop4 = firstObject.prop4; finalObject.prop5 = firstObject.prop5;
Create new object while copying
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = { prop0: firstObject.prop0, prop1: firstObject.prop1, prop2: firstObject.prop2, prop3: firstObject.prop3, prop4: firstObject.prop4, prop5: firstObject.prop5 };
Create new object from scratch
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 };
StructuredClone
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = structuredClone(firstObject);
JSON
const firstObject = { prop0: 'Hello world', prop1: 1, prop2: 2, prop3: "3", prop4: false, prop5: 0.2 }; const finalObject = JSON.parse(JSON.stringify(firstObject));

Run results for: JavaScript fastest way to clone an object including JSON.parse and structuredClone methods

Using the spread operator

Using Object.assign

Manually copying properties

Create new object while copying

Create new object from scratch

StructuredClone

JSON