Benchmark: JSON.parse vs string.split (big size)

Script Preparation code:

var array = new Array(500000).fill('1').map(() => Math.random().toString());
var str = JSON.stringify(array);

Tests:

JSON.parse
JSON.parse(str);
String.split
str.split(',')

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

String.split

62/s

JSON.parse

53/s

Fastest: String.split (1.2x faster)

View exact numbers

✓ String.split: 62 ops/sec
• JSON.parse: 53 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
JSON.parse
String.split

Fastest: N/A

Slowest: N/A

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/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

String.split

78/s

JSON.parse

56/s

View exact numbers

Test name	Executions per second
✓ String.split	78 Ops/sec
JSON.parse	56 Ops/sec

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

LLMs can make mistakes. Check important info.

The benchmark defined in the JSON tests the performance of two different approaches to parsing a string representation of an array: using `JSON.parse` and using `String.split`. This particular test focuses on a large dataset (an array of 500,000 elements, each being a randomly generated string) to evaluate how each method handles parsing this large string.

### Options Compared:

1. **JSON.parse**
   - **Description**: This method is a built-in JavaScript function for parsing JSON strings into JavaScript objects. In this case, it converts the string representation of an array back into an array.
   - **Pros**:
     - Directly deals with valid JSON format, providing a straightforward way to convert a string representation of an array into an array.
     - Handles nested structures and different data types naturally (if applicable).
   - **Cons**:
     - Can be slightly slower for very specific string formats if compared against optimized string manipulation methods.
     - Only applicable for valid JSON strings and may throw errors for improperly formatted strings.

2. **String.split**
   - **Description**: This method splits a string into an array of substrings based on a specified delimiter—in this case, the comma `,`. 
   - **Pros**:
     - Simpler for cases where you only need to split a string into parts based on a delimiter, which can sometimes lead to faster performance.
     - Very flexible, allowing the use of any delimiter and being less strict about input format than JSON.
   - **Cons**:
     - Requires post-processing if the items are not directly usable (for example, converting strings back to the desired form).
     - Does not handle complex objects or nested arrays well, as it simply creates substrings based on the presence of the delimiter.

### Considerations:
- The benchmark results show that `JSON.parse` executed approximately 20.85 executions per second, whereas `String.split` achieved about 19.20 executions per second. In this case, `JSON.parse` outperformed `String.split`, which indicates that the JSON handling in JavaScript is optimized for such use cases.
- Competition for performance might shift depending on the specific structure of the string being parsed and the environment where the code runs (e.g., different browsers may have different optimizations for these functions).
- Memory consumption and error handling during parsing can also be critical, especially when dealing with large datasets. `JSON.parse` will throw an error for malformed strings, while `String.split` will simply give you incorrect elements.

### Alternatives:
Other alternatives that can be considered depending on the specific use case include:
- **Manual Parsing**: Writing custom logic to parse the string without libraries can sometimes yield the best performance but requires a thorough understanding of the format and is inherently error-prone.
- **Regular Expressions**: Using regex with `String.match` can also parse strings based on patterns and could be faster for certain structured data.
- **Other Libraries**: If the need for more robust parsing arises (e.g., handling complex nested structures or various data types), libraries such as `lodash` or others that facilitate data manipulation may offer additional functionality, albeit at the expense of overhead.

In summary, this benchmark examines the effectiveness and efficiency of parsing large JSON strings into arrays, highlighting how different strategies yield varied performance and flexibility based on the requirements of the task.

JSON.parse vs string.split (big size) (version: 1)

Comparing performance of: `JSON.parse vs String.split`

Created: one year ago by: Guest

Go to the latest result

JSON.parse

String.split

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

JSON.parse vs string.split (big size) (version: 1)

Comparing performance of: JSON.parse vs String.split

Created: one year ago by: Guest

Go to the latest result

JSON.parse

String.split

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `JSON.parse vs String.split`