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; rv:143.0) Gecko/20100101 Firefox/143.0

Browser: Firefox 143

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 9 months ago

Object.assign

61.7M/s

spread

25.3M/s

structuredClone

2.0M/s

JSON.stringify

1.9M/s

View exact numbers

Test name	Executions per second
✓ Object.assign	61,702,624 Ops/sec
spread	25,307,286 Ops/sec
structuredClone	1,981,056 Ops/sec
JSON.stringify	1,878,775 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);