Benchmark: JSON.stringify vs structuredClone more

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...'
    },
    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...'
    },
    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...'
    },
    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...'
    },
    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...'
    },
    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...'
    },
    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...'
    },
    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...'
    },
    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);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
JSON.stringify
structuredClone

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36

Browser/OS: Chrome 105 on Windows

View result in a separate tab

Test name	Executions per second
JSON.stringify	388553.1 Ops/sec
structuredClone	239793.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark definition and analyze what's being tested.

**Benchmark Definition**

The benchmark compares two approaches to create a deep copy of an object:

1. `JSON.stringify` (also known as "stringify")
2. `structuredClone`

**Options Compared**

Both methods are compared for their performance, specifically in terms of the number of executions per second.

**Pros and Cons of Each Approach:**

1. **`JSON.stringify`**:
	* Pros:
		+ Widely supported by most JavaScript implementations.
		+ Easy to understand and implement.
	* Cons:
		+ Can be slow for large objects due to the overhead of converting JavaScript values to JSON strings.
		+ May not preserve all properties, especially those with non-JSON data types (e.g., functions).
2. **`structuredClone`**:
	* Pros:
		+ Specifically designed for deep copying, making it more efficient and reliable than `JSON.stringify`.
		+ Preserves all properties, including functions and non-JSON data types.
	* Cons:
		+ Less widely supported compared to `JSON.stringify`, with some older JavaScript implementations not supporting it.

**Library Used**

`structuredClone` is a built-in JavaScript function introduced in ECMAScript 2020 (ES2020). It's designed for deep cloning and preserving the structure of objects, arrays, and other data types. The purpose of this function is to provide a more efficient and reliable alternative to `JSON.stringify`.

**Special JS Feature/Syntax**

This benchmark does not use any special JavaScript features or syntax beyond what's required by the built-in functions being tested (`structuredClone`).

**Other Alternatives**

If you needed to create a deep copy of an object without using `structuredClone`, you could implement your own custom cloning function, such as:

```javascript
function cloneObject(obj) {
  if (typeof obj !== 'object') return obj;
  const result = Array.isArray(obj) ? [] : {};
  for (const key in obj) {
    if (Object.prototype.hasOwnProperty.call(obj, key)) {
      result[key] = cloneObject(obj[key]);
    }
  }
  return result;
}
```

However, this approach is generally less efficient and more error-prone than using `structuredClone`.

Related benchmarks:

JSON.stringify vs structuredClone more (version: 0)

JSON.stringify vs structuredClone

Comparing performance of: JSON.stringify vs structuredClone

Created: 2 years ago by: Guest

Jump to the latest result

JSON.stringify

structuredClone

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):