Run results for: JSON.stringify + JSON.parse vs structuredClone

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 months ago

JSON.stringify + JSON.parse

4.1M/s

structuredClone

1.4M/s

View exact numbers

Test name	Executions per second
✓ JSON.stringify + JSON.parse	4,134,433 Ops/sec
structuredClone	1,372,882 Ops/sec

Script Preparation code:

var obj = {
  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...'
  }
};

Tests:

JSON.stringify + JSON.parse
JSON.parse(JSON.stringify(obj));
structuredClone
structuredClone(obj);