Benchmark: lodash.isEqual vs fast-deep-equal vs JSON.stringify

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.20/lodash.min.js"></script>

Script Preparation code:

function equal(a, b) {
  if (a === b) return true;

  if (a && b && typeof a == 'object' && typeof b == 'object') {
    if (a.constructor !== b.constructor) return false;

    var length, i, keys;
    if (Array.isArray(a)) {
      length = a.length;
      if (length != b.length) return false;
      for (i = length; i-- !== 0;)
        if (!equal(a[i], b[i])) return false;
      return true;
    }



    if (a.constructor === RegExp) return a.source === b.source && a.flags === b.flags;
    if (a.valueOf !== Object.prototype.valueOf) return a.valueOf() === b.valueOf();
    if (a.toString !== Object.prototype.toString) return a.toString() === b.toString();

    keys = Object.keys(a);
    length = keys.length;
    if (length !== Object.keys(b).length) return false;

    for (i = length; i-- !== 0;)
      if (!Object.prototype.hasOwnProperty.call(b, keys[i])) return false;

    for (i = length; i-- !== 0;) {
      var key = keys[i];

      if (!equal(a[key], b[key])) return false;
    }

    return true;
  }

  // true if both NaN, false otherwise
  return a!==a && b!==b;
};

// 1 level deep
var data = [
                    {
                        description: 'equal numbers',
                        value1: 1,
                        value2: 1,
                        equal: true,
                    },
                    {
                        description: 'not equal numbers',
                        value1: 1,
                        value2: 2,
                        equal: false,
                    },
                    {
                        description: 'number and array are not equal',
                        value1: 1,
                        value2: [],
                        equal: false,
                    },
                    {
                        description: '0 and null are not equal',
                        value1: 0,
                        value2: null,
                        equal: false,
                    },
                    {
                        description: 'equal strings',
                        value1: 'a',
                        value2: 'a',
                        equal: true,
                    },
                    {
                        description: 'big object',
                        value1: {
                            prop1: 'value1',
                            prop2: 'value2',
                            prop3: 'value3',
                            prop4: {
                                subProp1: 'sub value1',
                                subProp2: {
                                    subSubProp1: 'sub sub value1',
                                    subSubProp2: [
                                        1,
                                        2,
                                        { prop2: 1, prop: 2 },
                                        4,
                                        5,
                                    ],
                                },
                            },
                            prop5: 1000,
                            prop6: new Date(2016, 2, 10),
                        },
                        value2: {
                            prop5: 1000,
                            prop3: 'value3',
                            prop1: 'value1',
                            prop2: 'value2',
                            prop6: new Date('2016/03/10'),
                            prop4: {
                                subProp2: {
                                    subSubProp1: 'sub sub value1',
                                    subSubProp2: [
                                        1,
                                        2,
                                        { prop2: 1, prop: 2 },
                                        4,
                                        5,
                                    ],
                                },
                                subProp1: 'sub value1',
                            },
                        },
                        equal: true,
                    },
                ];

Tests:

lodash
data.forEach((item) => { _.isEqual(item.value1, item.value2); });
fast-deep-equal
data.forEach((item) => { equal(item.value1, item.value2); });
JSON.stringify
data.forEach((item) => { JSON.stringify(item.value1) === JSON.stringify(item.value2); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash
fast-deep-equal
JSON.stringify

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 11 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Browser/OS: Chrome 138 on Mac OS X 10.15.7

View result in a separate tab

fast-deep-equal

2.2M/s

lodash

632K/s

JSON.stringify

350K/s

View exact numbers

Test name	Executions per second
✓ fast-deep-equal	2,160,949 Ops/sec
lodash	632,390 Ops/sec
JSON.stringify	350,096 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided benchmark compares the performance of three functions: `lodash.isEqual`, `fast-deep-equal`, and `JSON.stringify`. The goal is to determine which function is faster for comparing two values.

**Options Compared**

1. **Lodash's isEqual**: A popular utility function that checks if two values are equal, considering various types such as objects, arrays, numbers, strings, dates, and more.
2. **Fast-Deep-Equal**: A lightweight function designed to compare two values deeply, handling complex data structures like nested objects and arrays.
3. **JSON.stringify**: A built-in JavaScript method that converts a value into a JSON string, which can be used for comparison.

**Pros and Cons of Each Approach**

1. **Lodash's isEqual**:
	* Pros: Comprehensive comparison, handles various types, and is widely used.
	* Cons: Can be slow due to its complexity, especially for large data structures.
2. **Fast-Deep-Equal**:
	* Pros: Lightweight, fast, and specifically designed for deep comparisons.
	* Cons: May not handle all edge cases (e.g., NaN), and its implementation might not be as comprehensive as Lodash's isEqual.
3. **JSON.stringify**:
	* Pros: Simple, fast, and easy to implement.
	* Cons: Only compares values by converting them to strings, which may lead to inaccurate results for complex data structures.

**Library and Purpose**

The `lodash` library provides a wide range of utility functions, including `isEqual`. The `fast-deep-equal` function is not a part of any popular JavaScript libraries, but it's likely that its implementation was created specifically for this benchmark.

**Benchmark Results**

The provided benchmark results show the execution speed of each function for the given test cases. The fastest execution time is achieved by `JSON.stringify`, followed closely by `fast-deep-equal`. Lodash's isEqual takes the third position, indicating that it may not be the best choice for this specific use case.

Keep in mind that these results might vary depending on the specific hardware, software configuration, and test cases used.

lodash.isEqual vs fast-deep-equal vs JSON.stringify (version: 0)

Comparing performance of: `lodash vs fast-deep-equal vs JSON.stringify`

Created: one year ago by: Guest

Go to the latest result

lodash

fast-deep-equal

JSON.stringify

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

lodash.isEqual vs fast-deep-equal vs JSON.stringify (version: 0)

Comparing performance of: lodash vs fast-deep-equal vs JSON.stringify

Created: one year ago by: Guest

Go to the latest result

lodash

fast-deep-equal

JSON.stringify

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `lodash vs fast-deep-equal vs JSON.stringify`