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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

spread

9.2M/s

Object.assign

7.9M/s

JSON.stringify

1.0M/s

structuredClone

429K/s

View exact numbers

Test name	Executions per second
✓ spread	9,179,293 Ops/sec
Object.assign	7,927,801 Ops/sec
JSON.stringify	1,029,026 Ops/sec
structuredClone	429,366 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);