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

Autogenerated LLM Sumamry (model llama3.2:3b, generated 19 days 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.

Latest run results:

Run details: (Test run date: 7 months 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

Test name	Executions per second
querySelector	1568046.0 Ops/sec
classList.contains	4936618.0 Ops/sec
querySelector after more HTML elements	875125.3 Ops/sec
classList.contains after more HTML elements	4812829.5 Ops/sec

Related benchmarks:

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: one year ago by: Guest

Jump to the latest result

querySelector

classList.contains

querySelector after more HTML elements

classList.contains after more HTML elements

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 19 days ago):