Benchmark: JSON.stringify + JSON.parse vs structuredClone vs fast_deep_clone (recursive)

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...'
  }
};

var myCopy = null;

Tests:

JSON.parse(JSON.stringify())
JSON.parse(JSON.stringify(obj));
structuredClone()
structuredClone(obj);
fast_deep_clone()
const fast_deep_clone = (obj) => { function cloneArray(a, fn) { var keys = Object.keys(a); var a2 = new Array(keys.length) for (const key of keys) { var k = keys[key]; var cur = a[k]; if (typeof cur !== 'object' || cur === null) { a2[k] = cur; } else { a2[k] = fn(cur); } } return a2; } if (typeof obj !== 'object' || obj === null) return obj; if (obj instanceof Date) return new Date(obj); if (Array.isArray(obj)) return cloneArray(obj, fast_deep_clone); if (obj.toString() !== '[object Object]') { return obj.toString(); } let value, key; const keys = Object.keys(obj); const outObject = {}; for (key of keys) { if (key) { value = obj[key]; outObject[key] = fast_deep_clone(value); } } return outObject; }; fast_deep_clone(obj);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
JSON.parse(JSON.stringify())
structuredClone()
fast_deep_clone()

Fastest: N/A

Slowest: N/A

ⓘ Get performance results from real users on your website with Request Metrics.

Website Performance Monitoring by Request Metrics

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36

Browser/OS: Chrome 112 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
JSON.parse(JSON.stringify())	719232.6 Ops/sec
structuredClone()	614901.4 Ops/sec
fast_deep_clone()	1704038.0 Ops/sec

JSON.stringify + JSON.parse vs structuredClone vs fast_deep_clone (recursive) (version: 5)

Comparing performance of: JSON.parse(JSON.stringify()) vs structuredClone() vs fast_deep_clone()

Created: one year ago by: Registered User

Jump to the latest result

JSON.parse(JSON.stringify())

structuredClone()

fast_deep_clone()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A