Benchmark: TreeWalker vs querySelectorAll vs NodeIterator + filter HTMLElement

HTML Preparation code:

<!-- article out start -->
<article>
  <!-- article in start -->
  <h1>Lorem ipsum</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
  <!-- article in end -->
</article>
<!-- article out end -->

<!-- article out start -->
<article>
  <!-- article in start -->
  <h1>Lorem ipsum</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
  <!-- article in end -->
</article>
<!-- article out end -->

<!-- article out start -->
<article>
  <!-- article in start -->
  <h1>Lorem ipsum</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
  <!-- article in end -->
</article>
<!-- article out end -->

Tests:

TreeWalker
const treeWalker = document.createTreeWalker( document.body, NodeFilter.SHOW_ELEMENT, ); const list = []; let element; while (element = treeWalker.nextNode()) { list.push(element); } const elements = list.filter(el => el instanceof HTMLElement);
querySelectorAll
const elements = Array.from(document.body.querySelectorAll('*')).filter(node => node instanceof HTMLElement);
NodeIterator
const nodeIterator = document.createNodeIterator( document.body, NodeFilter.SHOW_ELEMENT, ); const list = []; let element; while (element = nodeIterator.nextNode()) { list.push(element); } const elements = list.filter(el => el instanceof HTMLElement);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
TreeWalker
querySelectorAll
NodeIterator

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:135.0) Gecko/20100101 Firefox/135.0

Browser/OS: Firefox 135 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
TreeWalker	957828.6 Ops/sec
querySelectorAll	1055229.0 Ops/sec
NodeIterator	966471.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**What is being tested?**

The provided benchmark compares three methods to retrieve all HTML elements from an article element in a web page:

1. **TreeWalker**: An API that allows traversing the DOM (Document Object Model) using a tree-like structure.
2. **querySelectorAll**: A method that selects multiple elements based on a CSS selector or XPath expression.
3. **NodeIterator + filter HTMLElement**: A combination of NodeIterator and a filter function to retrieve all HTML elements.

**Options compared**

The benchmark compares the performance of these three methods, which can be summarized as follows:

* TreeWalker:
	+ Uses a tree-like structure to traverse the DOM
	+ More efficient for traversing complex documents with multiple levels of nesting
	+ Can be slower for simple documents due to overhead in creating and managing the walker
* querySelectorAll:
	+ Uses a CSS selector or XPath expression to select elements
	+ Faster than TreeWalker for simple documents, as it only needs to parse the selector once
	+ Can be slower for complex documents due to the need to compute the selector
* NodeIterator + filter HTMLElement:
	+ Uses an iterator-like structure to traverse the DOM
	+ More efficient for large documents, as it allows for more control over the traversal process
	+ Requires additional memory and processing power due to the use of a separate iterator

**Pros and Cons**

Here's a summary of the pros and cons of each method:

* TreeWalker:
	+ Pros: Efficient for traversing complex documents, can be used for complex DOM manipulations.
	+ Cons: Can be slower for simple documents due to overhead in creating and managing the walker.
* querySelectorAll:
	+ Pros: Faster than TreeWalker for simple documents, reduces memory usage by only parsing the selector once.
	+ Cons: May not work as expected for complex selectors or documents with multiple levels of nesting.
* NodeIterator + filter HTMLElement:
	+ Pros: Efficient for large documents, allows for more control over traversal process.
	+ Cons: Requires additional memory and processing power due to the use of a separate iterator.

**Library and syntax**

The benchmark uses the following libraries and syntax:

* `document.createTreeWalker()`: Creates a new TreeWalker object that traverses the DOM in a tree-like structure.
* `Array.from()` and `querySelectorAll('*')`: These methods are part of the modern JavaScript API, introduced in ECMAScript 2015 (ES6).
* `NodeIterator` and `filter()`: These methods are also part of the modern JavaScript API, introduced in ECMAScript 2014 (ES6).

**Other considerations**

When choosing between these methods, consider the following factors:

* Complexity of the document: TreeWalker is more suitable for complex documents with multiple levels of nesting.
* Performance requirements: querySelectorAll may be faster for simple documents, while NodeIterator + filter HTMLElement is better suited for large documents.
* Memory constraints: querySelectorAll reduces memory usage by only parsing the selector once.

**Alternatives**

If you're looking for alternatives to these methods, consider:

* `querySelector()` or `getElementById()`: These methods are simpler and more straightforward but may not be as efficient as the other options.
* `DOMParser` API: This API allows parsing HTML documents from a string, which can be useful in certain scenarios.

In summary, this benchmark compares three methods for retrieving all HTML elements from an article element in a web page. TreeWalker is suitable for complex documents, while querySelectorAll and NodeIterator + filter HTMLElement are better suited for large documents or simple documents with performance requirements.

Related benchmarks:

TreeWalker vs querySelectorAll vs NodeIterator + filter HTMLElement (version: 7)

Comparing performance of: TreeWalker vs querySelectorAll vs NodeIterator

Created: 3 years ago by: Registered User

Jump to the latest result

TreeWalker

querySelectorAll

NodeIterator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):