Benchmark: parentElement/nextElement vs querySelector

HTML Preparation code:


<div id=''>
	<div id=''>
  		<div id='start'></div>
	</div>
</div>
<div id='end'></div>

Script Preparation code:

let start = document.querySelector('#start');

Tests:

querySelector
document.querySelector('#end');
parentElement/nextElement
start.parentElement.parentElement.nextElementSibling;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
querySelector
parentElement/nextElement

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:136.0) Gecko/20100101 Firefox/136.0

Browser/OS: Firefox 136 on Windows

View result in a separate tab

Test name	Executions per second
querySelector	7525431.5 Ops/sec
parentElement/nextElement	2795226368.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark on the website MeasureThat.net, which compares two approaches for accessing elements within an HTML document: `querySelector` and `parentElement/nextElement`. The benchmark aims to determine which approach is faster in different scenarios.

**Options Compared**

Two options are compared:

1. **`document.querySelector('#end')`**: This method uses the DOM query API (`querySelector`) to select an element by its ID.
2. **`start.parentElement.parentElement.nextElementSibling`**: This expression uses a combination of methods from the `Window` object and the DOM (`parentElement`, `nextElementSibling`) to access an element.

**Pros and Cons**

*   **`document.querySelector('#end')`**:
    *   Pros: Simple, widely supported, and efficient for direct selectors.
    *   Cons: May be slower for more complex queries or those that require parsing a CSS selector string.
*   **`start.parentElement.parentElement.nextElementSibling`**:
    *   Pros: Can be faster for accessing elements in a specific order, especially when the document structure is predictable (e.g., using `parentElement`, `nextElementSibling`, and `previousElementSibling` in sequence).
    *   Cons: Requires more DOM traversal, which can introduce overhead due to additional method calls.

**Library**

The `querySelectorAll` function from the W3C's DOM specification is used under the hood for both methods. However, since it's a built-in JavaScript method, no library needs to be included in this benchmark.

No special JavaScript features or syntax are required for these test cases. They only use standard ECMAScript 2020 features.

**Other Alternatives**

For similar benchmarks, consider:

*   Using `querySelectorAll` instead of `querySelector`, as it provides a way to select multiple elements and allows for more flexible filtering.
*   Adding additional methods or properties to the DOM object (e.g., `getElementsByClassName`, `getElementsByTagName`) to test their performance in various scenarios.

**Benchmark Preparation Code**

The provided HTML structure includes two `<div>` elements with nested `<div>` structures, which serve as the root element (`start`) and a target element (`#end`). The JavaScript code uses these elements in both test cases.

Related benchmarks:

parentElement/nextElement vs querySelector (version: 0)

parentElement/nextElement vs querySelector

Comparing performance of: querySelector vs parentElement/nextElement

Created: 3 years ago by: Guest

Jump to the latest result

querySelector

parentElement/nextElement

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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