Run results for: JSON.stringify vs structuredClone vs spread vs Object.assign()

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser: Chrome 141

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 10 months ago

spread

11.3M/s

Object.assign

10.7M/s

JSON.stringify

1.3M/s

structuredClone

277K/s

View exact numbers

Test name	Executions per second
✓ spread	11,298,334 Ops/sec
Object.assign	10,682,555 Ops/sec
JSON.stringify	1,336,956 Ops/sec
structuredClone	276,569 Ops/sec

Script Preparation code:

var MyObject = {
  description: 'Creates a deep copy of source, which should be an object or an array.',
  myNumber: 123456789,
  myBoolean: true,
  jayson: {
    stringify: 'JSON.stringify() method converts a JavaScript value to a JSON string....',
    parse: 'JSON.parse() method parses a JSON string...'
  }
};

var myCopy = null;

Tests:

JSON.stringify
myCopy = JSON.parse(JSON.stringify(MyObject));
structuredClone
myCopy = structuredClone(MyObject);
spread
myCopy = {...MyObject};
Object.assign
myCopy = Object.assign({}, MyObject);