Benchmark: Obj.is vs JSON.stringify

Script Preparation code:

const obj1 = { hello: "test", num: 10, obj: { "new": true }, arr: [1, 0] }
const obj2 = { hello: "test", num: 10, obj: { "new": false }, arr: [1, 2, 6] }

Tests:

Object.is
Object.is(obj1, obj2)
JSON.stringify
JSON.stringify(obj1) === JSON.stringify(obj2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.is
JSON.stringify

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.is	8418483.0 Ops/sec
JSON.stringify	2478928.5 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one month ago):

LLMs can make mistakes. Check important info.

The benchmark provided tests two different methods for comparing JavaScript objects: `Object.is` and `JSON.stringify`. Here’s a detailed explanation of what each method does, their pros and cons, and considerations for when to use them.

### Benchmark Overview

1. **Object.is**
   - **Benchmark Definition**: `Object.is(obj1, obj2)`
   - **Purpose**: This method compares two values for strict equality, taking into consideration some specific rules that differ from the `===` operator.
   - **Performance**: The benchmark illustrates that `Object.is` can handle comparisons very efficiently, achieving approximately 8.4 million executions per second on the tested environment.
   
2. **JSON.stringify**
   - **Benchmark Definition**: `JSON.stringify(obj1) === JSON.stringify(obj2)`
   - **Purpose**: This method converts the objects into JSON strings and then compares these strings for equality.
   - **Performance**: The benchmark indicates that `JSON.stringify` is less efficient, with about 2.5 million executions per second, showing a considerable decrease in performance compared to `Object.is`.

### Comparison of Approaches

#### Object.is
- **Pros**:
  - **Simple and Efficient**: Directly compares two references or values for equality without needing to convert them to another form.
  - **Handles Special Cases Correctly**: Unlike strict equality (`===`), `Object.is` correctly handles edge cases, such as distinguishing between `+0` and `-0`, and NaN is considered equal to NaN.
  - **Range**: Can compare primitives and references directly.

- **Cons**:
  - **Limited Use Cases**: Only suitable for determining if two references point to the same object or if two primitive values are the same. It does not perform deep comparisons, meaning it cannot determine if two objects with the same structure and values are equal.

#### JSON.stringify
- **Pros**:
  - **Deep Comparison**: Performs a deeper comparison based on the string representation of the objects. This enables the detection of structural similarities between complex objects.
  - **Easy to Use for Simple Structures**: Very easy to implement for one-off comparisons of simple objects.

- **Cons**:
  - **Performance Overhead**: The conversion process to a JSON string introduces a performance cost, as it involves serializing the entire object tree.
  - **Ignores Functions and Symbol Properties**: Functions, symbols, and undefined values are omitted from the resulting string.
  - **Order Sensitivity**: The order of keys matters since JSON.stringify does not guarantee that key order will remain consistent across different JavaScript engines.

### Other Considerations
For JavaScript developers, the choice between using `Object.is` and `JSON.stringify` will depend largely on the context of the comparison:

- **If you only need to compare simple types or references**: `Object.is` is the most efficient choice.
- **For deep equality checks between object structures**: While `JSON.stringify` is a quick way to achieve this, developers should consider libraries like **Lodash**'s `_.isEqual` which offer more robust solutions that handle various edge cases (e.g., ignoring property order, handling functions, and so on).
  
### Alternatives
- **Using `===`**: The strict equality operator can compare primitive values and object references, but does not handle the same nuances as `Object.is`.
- **Lodash or Underscore**: These libraries provide methods like `_.isEqual` to compare objects deeply, taking care of many edge cases that simple stringification would miss.
- **Deep comparison utilities**: Libraries such as `deep-equal` or `fast-equals` can also be utilized for deep comparisons with potentially better performance than `JSON.stringify`.

By understanding these differences, developers can make informed decisions based on their specific needs when comparing JavaScript objects.

Related benchmarks:

Obj.is vs JSON.stringify (version: 1)

Comparing performance of: Object.is vs JSON.stringify

Created: one month ago by: Guest

Jump to the latest result

Object.is

JSON.stringify

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one month ago):