Benchmark: getElementsByClassName, querySelector

HTML Preparation code:

<div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div> <div class="div1"><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><h1>H1</h1><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><span>stuff</span><h2>h2</h2></div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div><div>stuff</div>

Tests:

getElementsByClassName
document.getElementsByClassName("div1")
querySelector
document.querySelector(".div1")
speed find
$.find('.div1')
selector
$('.div1')
j
$(document.getElementsByClassName("div1"))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementsByClassName
querySelector
speed find
selector
j

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36

Browser/OS: Chrome 66 on Mac OS X 10.13.3

View result in a separate tab

Test name	Executions per second
getElementsByClassName	3637227.2 Ops/sec
querySelector	320583.0 Ops/sec
speed find	1041159.3 Ops/sec
selector	605474.8 Ops/sec
j	344037.2 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated 2 months ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark tests.

**Benchmark Overview**

The provided JSON represents a set of benchmark tests to compare the performance of different methods for selecting elements on a web page using JavaScript. The tests are designed to measure how quickly each method can execute in various browsers and environments.

**Test Cases**

There are five test cases:

1. **getElementsByClassName**: This test case uses the `document.getElementsByClassName()` method to select all elements with the class "div1".
2. **querySelector**: This test case uses the `document.querySelector()` method to select the first element with the class "div1".
3. **speed find** (using jQuery): This test case uses the jQuery library's `$().find()` method to select all elements with the class "div1".
4. **selector** (using jQuery): This test case uses the jQuery library's `$()` method to select all elements with the class "div1".
5. **j**: This test case appears to be using a combination of `document.getElementsByClassName()` and jQuery, but it's not entirely clear what this test is trying to measure.

**Library Usage**

The **speed find** and **selector** test cases use the jQuery library, which is a popular JavaScript library for DOM manipulation and event handling. In these tests, jQuery is used to select elements on the page using its `$()` method or `.find()` method.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax being tested in this benchmark.

**Options Compared**

The test cases compare the performance of different methods for selecting elements on a web page:

* `document.getElementsByClassName()`
* `document.querySelector()`
* jQuery's `$().find()`
* jQuery's `$()`

**Pros/Cons and Considerations**

Here are some pros and cons to consider when choosing between these methods:

* **Performance**: The results show that using `document.getElementsByClassName()` is generally faster than the other methods, especially for large numbers of elements. However, this may not be the case in all browsers or environments.
* **Browser Support**: `document.getElementsByClassName()` has good browser support, while `document.querySelector()` is also widely supported but may have some quirks in older browsers. jQuery's methods are generally well-supported across most modern browsers.
* **Ease of Use**: The jQuery library provides a more concise and intuitive way to select elements, especially when working with complex queries.

**Other Alternatives**

Other alternatives for selecting elements on a web page include:

* Using the `document.querySelectorAll()` method (not tested in this benchmark)
* Using CSS selectors directly in JavaScript (e.g., using `document.querySelector('.div1')`)
* Using other JavaScript libraries or frameworks, such as Lodash or VanillaJS

Keep in mind that the results of this benchmark may not be universally applicable and should be taken as a general guideline rather than an absolute truth. The best approach will depend on your specific use case and requirements.

Related benchmarks:

getElementsByClassName, querySelector (version: 0)

Comparing performance of: getElementsByClassName vs querySelector vs speed find vs selector vs j

Created: 6 years ago by: Guest

Jump to the latest result

getElementsByClassName

querySelector

speed find

selector

j

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated 2 months ago):