Benchmark: parentNode vs firstChild vs nextSibling vs previousSibling (plus bonus: firstChild.nextSibling, querySelectorAll)

HTML Preparation code:

<html>

<body>
    <div id='test'><div class='child'></div><div></div><div></div></div>
</body>

</html>

Script Preparation code:

var parent = document.getElementById('test');
var child1 = parent.children[0]
var child2 = parent.children[1]

Tests:

parentNode
let n = child1.parentNode;
firstChild
let n = parent.firstChild;
nextSibling
let n = child1.nextSibling
previousSibling
let n = child2.previousSibling
firstChild.nextSibling
let n = parent.firstChild.nextSibling
querySelectorAll
let n = parent.querySelectorAll(".child")[0]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
parentNode
firstChild
nextSibling
previousSibling
firstChild.nextSibling
querySelectorAll

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 11 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2.1 Safari/605.1.15

Browser/OS: Safari 17 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
parentNode	30653476.0 Ops/sec
firstChild	29747742.0 Ops/sec
nextSibling	29740668.0 Ops/sec
previousSibling	29785298.0 Ops/sec
firstChild.nextSibling	27951970.0 Ops/sec
querySelectorAll	6172009.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark and explore what's being tested, the different approaches compared, their pros and cons, and other considerations.

**What's being tested?**

The provided JSON represents a JavaScript microbenchmarking test case, specifically designed to measure the performance of various methods for finding nodes in a DOM tree. The test cases focus on the following methods:

1. `parentNode`
2. `firstChild`
3. `nextSibling`
4. `previousSibling`
5. `firstChild.nextSibling` (a more specific variant of `firstChild`)
6. `querySelectorAll`

**Approaches compared**

The benchmark compares the performance of each method, which can be summarized as follows:

* **DOM traversal**: Methods that navigate the DOM tree to find a node, such as `parentNode`, `nextSibling`, and `previousSibling`. These approaches are based on traversing the DOM tree from the top down.
* **Direct access**: Methods that directly access the node's properties or methods, such as `firstChild` and `querySelectorAll`. This approach bypasses the DOM traversal.

**Pros and Cons**

Here's a brief summary of each method:

1. **DOM traversal (parentNode, nextSibling, previousSibling)**:
	* Pros: Simple to implement, well-supported by most browsers.
	* Cons: Can be slower due to the overhead of traversing the DOM tree.
2. **Direct access (firstChild, querySelectorAll)**:
	* Pros: Generally faster, as it bypasses the DOM traversal.
	* Cons: May require more complex implementation, and not all browsers support `querySelectorAll` for non-HTML elements.

**Library usage**

In this benchmark, no specific JavaScript library is used. The test code relies on native JavaScript methods to navigate the DOM tree.

**Special JS feature or syntax**

None of the tested methods rely on special JavaScript features or syntax, making them more widely compatible across browsers and platforms.

**Benchmark result interpretation**

The provided results show the performance of each method in terms of executions per second (ExecutionsPerSecond). The top-performing method is `querySelectorAll`, followed closely by `firstChild`. This suggests that direct access methods are generally faster than DOM traversal approaches.

**Other alternatives**

For this specific benchmark, there aren't many alternatives. However, other JavaScript microbenchmarks might explore different aspects of performance, such as:

* Garbage collection and memory allocation
* Function call optimization
* String manipulation and regex processing

Keep in mind that the choice of benchmarking method depends on the specific use case and requirements.

In summary, this benchmark measures the performance of various methods for finding nodes in a DOM tree. The results suggest that direct access methods are generally faster than DOM traversal approaches.

Related benchmarks:

parentNode vs firstChild vs nextSibling vs previousSibling (plus bonus: firstChild.nextSibling, querySelectorAll) (version: 0)

Fastest way to find nodes

Comparing performance of: parentNode vs firstChild vs nextSibling vs previousSibling vs firstChild.nextSibling vs querySelectorAll

Created: 11 months ago by: Guest

Jump to the latest result

parentNode

firstChild

nextSibling

previousSibling

firstChild.nextSibling

querySelectorAll

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):