Benchmark: querySelector(class) vs classList.contains

HTML Preparation code:

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Script Preparation code:

function querySelectorWrapper(className) {
    return !document.querySelector('.' + className);
}

function classListContainsWrapper(element, className) {
    return element.classList.contains(className);
}
var elementRefB = document.querySelector('.b');
var elementRefC = document.querySelector('.c');

Tests:

querySelector
querySelectorWrapper('b');
classList.contains
classListContainsWrapper(elementRefB, 'b');
querySelector after more HTML elements
querySelectorWrapper('c');
classList.contains after more HTML elements
classListContainsWrapper(elementRefC, 'c');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
querySelector
classList.contains
querySelector after more HTML elements
classList.contains after more HTML elements

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36

Browser/OS: Chrome 123 on Windows

View result in a separate tab

classList.contains

4.9M/s

classList.contains after more HTML elements

4.8M/s

querySelector

1.6M/s

querySelector after more HTML elements

875K/s

View exact numbers

Test name	Executions per second
✓ classList.contains	4,936,618 Ops/sec
classList.contains after more HTML elements	4,812,830 Ops/sec
querySelector	1,568,046 Ops/sec
querySelector after more HTML elements	875,125 Ops/sec

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

LLMs can make mistakes. Check important info.

Based on the provided benchmark results, here are some observations and possible conclusions:

**Browser Performance**

The benchmark results show that Chrome 123 is performing well across all test cases.

* `classList.contains` executed at approximately 49,366,618 executions per second
* `classList.contains after more HTML elements` executed at approximately 48,132,829 executions per second
* `querySelector` executed at approximately 15,680,460 executions per second
* `querySelector after more HTML elements` executed at approximately 87,512,625 executions per second

**Device and OS**

The benchmark results are from a Windows desktop device.

**Operating System**

All benchmark results are from Windows operating system.

**Element Count**

The test cases with more HTML elements (`classList.contains after more HTML elements` and `querySelector after more HTML elements`) show slightly slower execution times compared to the basic test case (`classList.contains`).

However, it's essential to note that these differences in performance are relatively small and may not be statistically significant. Additionally, the results might be influenced by other factors such as JavaScript engine optimization, caching, and DOM manipulation.

**Conclusion**

While there is some variation in execution times between the different test cases, Chrome 123 appears to be performing well overall. The Windows desktop device and OS are also shown to provide a stable platform for benchmarking.

However, without more detailed analysis of the results or additional context, it's challenging to draw concrete conclusions about the performance characteristics of Chrome 123 on this specific hardware and software configuration.

querySelector(class) vs classList.contains (version: 0)

HTML DOM querySelector, vs looking into classList of element which already have

Comparing performance of: `querySelector vs classList.contains vs querySelector after more HTML elements vs classList.contains after more HTML elements`

Created: 2 years ago by: Guest

Go to the latest result

querySelector

classList.contains

querySelector after more HTML elements

classList.contains after more HTML elements

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

querySelector(class) vs classList.contains (version: 0)

HTML DOM querySelector, vs looking into classList of element which already have

Comparing performance of: querySelector vs classList.contains vs querySelector after more HTML elements vs classList.contains after more HTML elements

Created: 2 years ago by: Guest

Go to the latest result

querySelector

classList.contains

querySelector after more HTML elements

classList.contains after more HTML elements

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: `querySelector vs classList.contains vs querySelector after more HTML elements vs classList.contains after more HTML elements`