Benchmark: structuredClose(myObject) vs JSON.parse(JSON.stringify(myObject))

structuredClose(myObject) vs JSON.parse(JSON.stringify(myObject)) (version: 0)

Both structuredClone(myObject) and JSON.parse(JSON.stringify(myObject)) can be used to create deep copies of JavaScript objects, but which is faster for a decent sized object?

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

Created: one month ago by: Registered User

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Script Preparation code:

var myObject = {
    name: 'Jane Darlene',
    age: 25,
    score: 120,
    weight: 65.5,
    balabnce: 2000.0,
    premium: false,
    birthDate: '2024-10-02T03:23:58.663Z',
    testNull: null,
    title: 'Some other title',
    description: 'Some other description',
    address: {
        street: '123 Main St',
        city: 'Anytown',
        state: 'NY',
        zip: 12345,
        country: 'USA',
    },
    additionalAddresses: [{
            street: '456 Elm St',
            city: 'Anytown',
            state: 'NY',
            zip: 12345,
            country: 'USA',
        },
        {
            street: '789 Oak St',
            city: 'Anytown',
            state: 'NY',
            zip: 12345,
            country: 'USA',
        },
    ],
    profile: {
        firstName: 'Jane',
        lastName: 'Darlene',
    },
    features: ['One', 'Two', 'Three'],
    favorites: [{
            slug: 'first',
            postname: 'First post'
        },
        {
            slug: 'second',
            postname: 'Second post'
        },
    ],
    todos: {
        1: {
            id: 1,
            text: 'First todo',
            done: false
        },
        2: {
            id: 2,
            text: 'Second todo',
            done: true
        },
    },
};

Tests:

structuredClone(myObject)
structuredClone(myObject);
JSON.parse(JSON.stringify(myObject))
JSON.parse(JSON.stringify(myObject));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested, the options compared, their pros and cons, and other considerations.

**What's being tested:**

The benchmark is comparing two ways to create a deep copy of a JavaScript object:

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

Both methods are used to create a new, independent copy of the original object, but they differ in their implementation and potential performance.

**Options compared:**

The benchmark is comparing two options for creating a deep copy of a JavaScript object:

A) `structuredClone(myObject)`
B) `JSON.parse(JSON.stringify(myObject))`

**Pros and Cons:**

### A) `structuredClone(myObject)`

* **Pros:**
	+ Designed specifically for creating deep copies of objects, making it more efficient and safer than other methods.
	+ Implemented in a way that minimizes the creation of intermediate objects, which can lead to memory leaks.
* **Cons:**
	+ Introduced in ECMAScript 2021, so older browsers may not support it.
	+ May have slower performance compared to `JSON.parse(JSON.stringify(myObject))` due to its more complex implementation.

### B) `JSON.parse(JSON.stringify(myObject))`

* **Pros:**
	+ Widely supported by older browsers, as it's based on the standard JSON serialization mechanism.
	+ Generally faster than `structuredClone(myObject)` due to its simpler implementation.
* **Cons:**
	+ Not designed specifically for creating deep copies of objects, which can lead to issues with nested objects or cyclic references.
	+ Can create intermediate objects that consume more memory.

**Other considerations:**

* When working with large objects or complex data structures, `structuredClone(myObject)` might be a better choice due to its designed efficiency and safety features.
* However, for smaller objects or simpler data structures, the difference in performance between `structuredClone(myObject)` and `JSON.parse(JSON.stringify(myObject))` might not be noticeable.

**Library usage:**

In this benchmark, `structuredClone()` is used as a built-in JavaScript function, which means it's part of the ECMAScript standard. On the other hand, `JSON.stringify()` is also a built-in JavaScript function, but its purpose is to serialize objects into a JSON string, rather than create a deep copy.

**Special JS features or syntax:**

None mentioned in this benchmark.

**Alternatives:**

If you need a more efficient or safer way to create deep copies of objects, you can consider using other libraries or polyfills, such as:

* Lodash's `cloneDeep()`
* Underscore.js's `deepClone()`
* A library like `json-stable-stringify`

Keep in mind that these alternatives might introduce additional dependencies and may not be supported by older browsers.

Overall, the benchmark is testing two widely used methods for creating deep copies of JavaScript objects: `structuredClone()` and `JSON.parse(JSON.stringify(myObject))`. By comparing their performance and characteristics, developers can make informed decisions about which method to use in their own projects.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:131.0) Gecko/20100101 Firefox/131.0

Browser/OS: Firefox 131 on Windows

View result in a separate tab

Test name	Executions per second
structuredClone(myObject)	33920.0 Ops/sec
JSON.parse(JSON.stringify(myObject))	45901.5 Ops/sec

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