Benchmark: replaceAll vs regex replace

Script Preparation code:

String.prototype.replaceAll = function(search, replacement) {
    var target = this;
    return target.replace(new RegExp(search, 'g'), replacement);
};

Tests:

replace regex
"this is it".replace(/ /g, "+");
replace All
"this is it".replaceAll(" ", "+");

Historical Performance Data aggregated from 573 community runs

Desktop Results:

Chrome 394 runs

replace regex

10.5M/s

replace All

3.6M/s

Fastest: replace regex (2.9x faster)

View exact numbers

✓ replace regex: 10,507,260 ops/sec
• replace All: 3,613,556 ops/sec

Firefox 118 runs

replace regex

8.4M/s

replace All

3.5M/s

Fastest: replace regex (2.4x faster)

View exact numbers

✓ replace regex: 8,407,426 ops/sec
• replace All: 3,544,174 ops/sec

Safari 21 runs

replace regex

486.5M/s

replace All

5.7M/s

Fastest: replace regex (85.2x faster)

View exact numbers

✓ replace regex: 486,459,904 ops/sec
• replace All: 5,706,978 ops/sec

Other 10 runs

replace regex

12.7M/s

replace All

4.9M/s

Fastest: replace regex (2.6x faster)

View exact numbers

✓ replace regex: 12,712,996 ops/sec
• replace All: 4,933,345 ops/sec

Mobile Results:

Chrome 22 runs

replace regex

7.6M/s

replace All

2.2M/s

Fastest: replace regex (3.5x faster)

View exact numbers

✓ replace regex: 7,568,194 ops/sec
• replace All: 2,182,690 ops/sec

Safari 8 runs

replace regex

464.3M/s

replace All

5.1M/s

Fastest: replace regex (91.1x faster)

View exact numbers

✓ replace regex: 464,298,432 ops/sec
• replace All: 5,096,660 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
replace regex
replace All

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 18 hours ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:153.0) Gecko/20100101 Firefox/153.0

Browser/OS: Firefox 153 on Mac OS X 10.15

View result in a separate tab

replace regex

20.3M/s

replace All

8.8M/s

View exact numbers

Test name	Executions per second
✓ replace regex	20,346,992 Ops/sec
replace All	8,760,853 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark definition and test cases to explain what's being tested, compared, and their pros and cons.

**Benchmark Definition:**
The `replaceAll vs regex replace` benchmark is comparing two different approaches to replacing characters in a string:

1. **String.prototype.replaceAll**: A custom implementation of the `replaceAll` method on the `String` prototype.
2. **Regular Expression (regex) replace**: Using the built-in `replace()` method with a regular expression.

**Script Preparation Code:**
The script preparation code is providing the implementation for the custom `replaceAll` method:
```javascript
String.prototype.replaceAll = function(search, replacement) {
  var target = this;
  return target.replace(new RegExp(search, 'g'), replacement);
};
```
This implementation simply calls the built-in `replace()` method with a regular expression.

**Options Compared:**

1. **Custom `replaceAll` vs regex replace**: The benchmark is comparing the performance of the custom `replaceAll` method (using the script preparation code) against the built-in `replace()` method with regular expressions.
2. **Regex syntax**: Within each test case, different regex patterns are used to demonstrate the differences in behavior.

**Pros and Cons:**

1. **Custom `replaceAll` vs regex replace**:
	* **Pros**:
		+ Can be more efficient for certain use cases, as it avoids creating a regular expression object.
		+ Allows for custom behavior or optimizations.
	* **Cons**:
		+ May not work correctly for all edge cases or character sets.
		+ Can be less readable and maintainable than the built-in implementation.
2. **Regex syntax**:
	* **Pros**:
		+ Provides a flexible way to match patterns with varying complexity.
	* **Cons**:
		+ Can be slower due to the creation of regular expression objects.

**Library/Language Features:**

1. **String.prototype.replaceAll**: This is a custom implementation on the `String` prototype, which allows for simple and efficient string replacement.
2. **Regular Expression (regex)**: The built-in `replace()` method uses regular expressions under the hood, providing a powerful way to match patterns.

**Special JS Features/Syntax:**

There are no specific JavaScript features or syntax used in this benchmark that would be unique or special. However, it's worth noting that some older browsers might have different behavior for certain string methods due to implementation differences (e.g., `replace()` vs `replaceAll()`).

**Other Alternatives:**

1. **Using a library like js-regexp**: Instead of implementing regex from scratch, you could use an existing library like js-regexp, which provides a more efficient and reliable way to work with regular expressions.
2. **Using alternative string replacement libraries**: Depending on your specific use case, there might be other libraries or implementations that provide better performance or features than the built-in `replace()` method.

Keep in mind that the benchmark is primarily focused on comparing the performance of these two approaches, rather than exploring different alternatives or features.

replaceAll vs regex replace (version: 0)

Comparing performance of: `replace regex vs replace All`

Created: 8 years ago by: Guest

Go to the latest result

replace regex

replace All

Historical Performance Data aggregated from 573 community runs

Desktop Results:

Chrome 394 runs

Firefox 118 runs

Safari 21 runs

Other 10 runs

Mobile Results:

Chrome 22 runs

Safari 8 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

replaceAll vs regex replace (version: 0)

Comparing performance of: replace regex vs replace All

Created: 8 years ago by: Guest

Go to the latest result

replace regex

replace All

Historical Performance Data aggregated from 573 community runs

Desktop Results:

Chrome 394 runs

Firefox 118 runs

Safari 21 runs

Other 10 runs

Mobile Results:

Chrome 22 runs

Safari 8 runs

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: `replace regex vs replace All`