Benchmark: json.parse(stringify()) vs structuredClone

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 Clone
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 Clone
structuredClone

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON benchmark definition and test cases.

**Benchmark Definition:**

The benchmark measures the performance of two approaches for creating a deep copy of an object:

1. `JSON.parse(JSON.stringify(MyObject))`
2. `structuredClone(MyObject)`

**What is being tested?**

The benchmark tests the execution time of these two approaches on a specific JavaScript object (`MyObject`). The object contains nested properties, including another object with a string that describes its purpose.

**Options compared:**

Two options are compared:

1. **`JSON.parse(JSON.stringify(MyObject))`**: This approach uses the `JSON.parse()` method to parse a JSON representation of the object and then creates a new object from it.
2. **`structuredClone(MyObject)`**: This is a newer approach introduced in ECMAScript 2020, which creates a deep clone of an object without serializing it to a string.

**Pros and Cons:**

1. **`JSON.parse(JSON.stringify(MyObject))`**:
	* Pros:
		+ Widely supported by older browsers.
		+ Easy to implement.
	* Cons:
		+ Can be slower than `structuredClone()` due to the extra parsing step.
		+ May not work correctly with certain data types (e.g., symbols, sets).
2. **`structuredClone(MyObject)`**:
	* Pros:
		+ Faster execution time compared to `JSON.parse(JSON.stringify(MyObject))`.
		+ More efficient for large objects.
	* Cons:
		+ Requires modern browsers that support ECMAScript 2020 (Chrome 117 and above).
		+ Less widely supported by older browsers.

**Library:**

The benchmark uses the `structuredClone` function, which is a built-in JavaScript function introduced in ECMAScript 2020. Its purpose is to create a deep clone of an object without serializing it to a string.

**Special JS feature or syntax:**

None mentioned in the provided JSON.

**Other alternatives:**

If you need to support older browsers that don't have `structuredClone()` support, you can consider using:

1. **`JSON.parse(JSON.stringify(MyObject))`:**
	* A widely supported approach, but slower than `structuredClone()`.
2. **Manual deep cloning:**
	* Creating a new object and recursively copying its properties.
	* More verbose and error-prone, but provides more control over the cloning process.

In summary, `structuredClone()` is a newer, faster approach for creating a deep clone of an object, while `JSON.parse(JSON.stringify(MyObject))` is a widely supported, albeit slower alternative. The choice between these approaches depends on your specific requirements, browser support, and performance considerations.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Windows

View result in a separate tab

Test name	Executions per second
Json Clone	595856.1 Ops/sec
structuredClone	290476.2 Ops/sec

Related benchmarks:

json.parse(stringify()) vs structuredClone (version: 0)

Comparing performance of: Json Clone vs structuredClone

Created: one year ago by: Guest

Jump to the latest result

Json Clone

structuredClone

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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