Benchmark: Get Class - MeasureThat.net

HTML Preparation code:

<div class="test"></div>

Tests:

querySelector
document.querySelector(".test")
getElementsByClassName
document.getElementsByClassName(".test")
querySelectorAll
document.querySelectorAll('.test')
querySelectorAllWithAttribute
document.querySelectorAll(`[class*="dfp"]`)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
querySelector
getElementsByClassName
querySelectorAll
querySelectorAllWithAttribute

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

Browser/OS: Chrome 81 on Mac OS X 10.15.4

View result in a separate tab

Test name	Executions per second
querySelector	3382022.0 Ops/sec
getElementsByClassName	4128519.8 Ops/sec
querySelectorAll	1427467.1 Ops/sec
querySelectorAllWithAttribute	1007615.3 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript benchmark on MeasureThat.net, which compares the performance of different DOM selection methods in modern web browsers. The test cases aim to measure the execution speed of various selectors to identify the most efficient method.

**Test Cases and Comparisons**

1. `querySelector`
	* Test Case: `document.querySelector(".test")`
	* Purpose: Tests the use of the `querySelector` method, which selects the first element that matches a specified selector.
	* Pros: Simple and widely supported, makes it easy to target specific elements.
	* Cons: May not be as efficient as other methods for larger sets of elements or complex selectors.
2. `getElementsByClassName`
	* Test Case: `document.getElementsByClassName(".test")`
	* Purpose: Tests the use of the `getElementsByClassName` method, which returns a live HTMLCollection of elements that match a specified class name.
	* Pros: Returns all matching elements, can be useful for targeting elements with specific classes.
	* Cons: May return unnecessary elements if not properly filtered, can lead to slower performance.
3. `querySelectorAll`
	* Test Case: `document.querySelectorAll('.test')`
	* Purpose: Tests the use of the `querySelectorAll` method, which returns a NodeList of all matching elements that match a specified selector.
	* Pros: Returns all matching elements, provides more flexibility than individual methods.
	* Cons: May be less efficient for very large sets of elements or complex selectors.
4. `querySelectorAllWithAttribute`
	* Test Case: `document.querySelectorAll("[class*=\"dfp\"]")`
	* Purpose: Tests the use of the `querySelectorAll` method with an attribute selector, which returns a NodeList of elements that have a specific class name as part of their attributes.

**Library and Special Features**

The provided benchmark does not use any external libraries. However, it relies on the browser's built-in DOM APIs for DOM selection.

There are no special features or syntax used in this benchmark, such as async/await, Promises, or modern JavaScript features like arrow functions or template literals. The focus is on the performance comparison of basic DOM selection methods.

**Alternative Methods and Considerations**

Other alternative methods for DOM selection include:

* `document.querySelectorAll`: A deprecated method that returns a live HTMLCollection of matching elements.
* `Array.prototype.filter()`: Can be used to filter an array of element IDs or classes, but may not provide the same level of performance as native DOM methods.

When choosing a DOM selection method, consider factors like:

* Performance: How many elements are being targeted? Which method provides the best balance between speed and accuracy?
* Flexibility: Are you targeting specific class names, attributes, or CSS selectors?
* Browser support: Ensure that the chosen method is supported by the target browsers.

Keep in mind that browser performance may vary depending on factors like page load, JavaScript execution, and rendering. Testing different DOM selection methods can help identify the most efficient approach for a given use case.

Related benchmarks:

Get Class (version: 0)

Comparing performance of: querySelector vs getElementsByClassName vs querySelectorAll vs querySelectorAllWithAttribute

Created: 4 years ago by: Guest

Jump to the latest result

querySelector

getElementsByClassName

querySelectorAll

querySelectorAllWithAttribute

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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