Benchmark: whatwhat - MeasureThat.net

HTML Preparation code:

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

Tests:

document.querySelector
document.querySelector(".test")
document.getElementsByTagName[0]
document.getElementsByTagName("div")[0]
document.getElementsByClassName[0]
document.getElementsByClassName("test")[0]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
document.querySelector
document.getElementsByTagName[0]
document.getElementsByClassName[0]

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0

Browser/OS: Firefox 91 on Windows

View result in a separate tab

Test name	Executions per second
document.querySelector	3784952.0 Ops/sec
document.getElementsByTagName[0]	3731413.5 Ops/sec
document.getElementsByClassName[0]	3737275.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The JSON file defines a benchmark with two parts: Script Preparation Code and Html Preparation Code. The Script Preparation Code is empty, which means that no script needs to be executed before running the tests. However, the Html Preparation Code includes multiple HTML elements with a class of "test", which will likely be used as targets for the tests.

**Individual Test Cases**

There are three test cases defined:

1. `document.querySelector`
2. `document.getElementsByTagName[0]`
3. `document.getElementsByClassName[0]`

These test cases use the Document Object Model (DOM) to retrieve elements from a HTML document. The main difference between these test cases is how they select elements using different methods:

* `querySelector` uses a CSS selector syntax to find an element.
* `getElementsByTagName` returns all elements with a specific tag name and returns the first one as `[0]`.
* `getElementsByClassName` returns all elements with a specific class name and returns the first one as `[0]`.

**What's Being Tested**

The benchmark is testing the performance of these three methods in retrieving elements from a HTML document. The tests are likely measuring how quickly each method can execute, which can be important for web applications that need to perform DOM-based operations efficiently.

**Pros and Cons of Each Approach**

1. `querySelector`:
	* Pros: Fast and efficient, as it uses CSS selector syntax to find the first matching element.
	* Cons: May not be suitable for complex queries or large datasets.
2. `getElementsByTagName[0]`:
	* Pros: Simple and straightforward, as it returns the first element with a specific tag name.
	* Cons: Can be slow if there are many elements on the page, as it needs to iterate through all of them to find the first match.
3. `getElementsByClassName[0]`:
	* Pros: Fast for small datasets, as it only needs to search through a small set of elements with the specified class name.
	* Cons: Can be slow if there are many elements on the page with the same class name.

**Other Considerations**

* **Browser Support**: The benchmark likely assumes that the tests will be run in modern web browsers, such as Firefox 91. Other browsers may not support these methods or have different performance characteristics.
* **Device Platform and Operating System**: The benchmark includes device platform (Desktop) and operating system (Windows) information, which could affect the performance of each method.

**Library and Special JS Feature**

None of the test cases explicitly use a library or special JavaScript feature. However, it's worth noting that modern web browsers often include libraries like jQuery, which provides an abstraction layer for DOM-based operations. If these tests were run in a browser that doesn't have jQuery available, the performance differences between these methods might be more pronounced.

**Alternatives**

If you want to write your own benchmark or experiment with different performance characteristics, here are some alternatives:

* Use Node.js and its built-in `DOM` module (or a library like `jsdom`) to simulate DOM-based operations in a headless browser.
* Write a script that uses a library like Selenium WebDriver to automate web browsers and measure the execution time of each test case.
* Create a custom benchmarking framework using a programming language like Python or Java, which can be used to write and run benchmarks on different environments.

Related benchmarks:

whatwhat (version: 0)

Comparing performance of: document.querySelector vs document.getElementsByTagName[0] vs document.getElementsByClassName[0]

Created: 3 years ago by: Guest

Jump to the latest result

document.querySelector

document.getElementsByTagName[0]

document.getElementsByClassName[0]

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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