Benchmark: replaceChildren vs document fragment

HTML Preparation code:

<div id="container"></div>

Tests:

fragment
const container = document.getElementById("container"); const contents = [ document.createElement("div"), document.createElement("div"), document.createElement("div"), ]; const fragment = document.createDocumentFragment(); for (const child of contents) { fragment.appendChild(child); } container.appendChild(fragment);
replaceChildren
const container = document.getElementById("container"); const contents = [ document.createElement("div"), document.createElement("div"), document.createElement("div"), ]; container.replaceChildren(...contents);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
fragment
replaceChildren

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 2 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Overview**

The provided JSON represents a benchmark that compares the performance of two approaches: replacing children using `document.replaceChildren()` and using a `DocumentFragment` to append elements to the container.

**Options Compared**

Two options are being compared:

1. **`replaceChildren()`**: This method replaces the child nodes of an element with a new set of nodes, without creating a new DOM tree.
2. **`DocumentFragment`**: A fragment is a lightweight object that can hold a collection of nodes, which can be appended to another element.

**Pros and Cons**

### `replaceChildren()`

Pros:

* Lightweight: This approach does not create a new DOM tree, making it more efficient in terms of memory usage.
* Fast: Replacing children is typically faster than appending elements using a fragment.

Cons:

* Less control: When using `replaceChildren()`, you have less control over the order and timing of element updates.
* Potential issues with event listeners: If an element has event listeners attached to its child nodes, those listeners may not be triggered when replacing children.

### `DocumentFragment`

Pros:

* More control: Using a fragment allows for more control over the order and timing of element updates.
* Better support for event listeners: When using a fragment, event listeners attached to the child nodes will still be triggered.

Cons:

* Heavier: Creating a new fragment can be slower than replacing children directly, due to the overhead of creating a new DOM object.
* More memory-intensive: Fragments require more memory to store the collection of nodes.

**Other Considerations**

When deciding between these approaches, consider the specific requirements of your use case. If you need more control over element updates and event listeners, `DocumentFragment` might be a better choice. However, if you prioritize performance and don't mind sacrificing some control, `replaceChildren()` could be the way to go.

**Library Usage**

The benchmark uses the `document` object, which is part of the DOM (Document Object Model) API in JavaScript. The `document` object provides various methods for interacting with the DOM, including creating elements, fragments, and updating the document tree.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntaxes used in this benchmark that require explanation.

**Alternative Approaches**

Other alternatives to these approaches include:

* **Using a virtual DOM library**: Libraries like React or Vue.js use a virtual DOM (a lightweight, in-memory representation of the actual DOM) to optimize updates. While this approach can provide better performance and control, it often comes with additional overhead and complexity.
* **Applying CSS transformations instead of replacing children**: Some libraries or frameworks provide methods for applying CSS transformations to elements, which can be used to update the layout without replacing children.

In summary, the benchmark compares two approaches for updating the DOM: using `replaceChildren()` versus using a `DocumentFragment`. Each approach has its pros and cons, and the choice ultimately depends on the specific requirements of your use case.

Latest run results:

Run details: (Test run date: 7 days ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser/OS: Chrome 129 on Linux

View result in a separate tab

Test name	Executions per second
fragment	195094.3 Ops/sec
replaceChildren	131416.9 Ops/sec

Related benchmarks:

replaceChildren vs document fragment (version: 0)

Comparing performance of: fragment vs replaceChildren

Created: 7 days ago by: Registered User

Jump to the latest result

fragment

replaceChildren

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 2 days ago):