Benchmark: replaceChild vs replaceChildren vs documentFragment 2

HTML Preparation code:

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

Script Preparation code:

var elements = [document.createElement('div'), document.createElement('div')];
var fragment = document.createDocumentFragment();
var container = document.getElementById('container');

elements.forEach(element => fragment.appendChild(element));
container.appendChild(fragment);

Tests:

replaceChild
var changeIndex = 1; elements[changeIndex] = document.createElement('div'); container.replaceChild(elements[changeIndex], container.children[changeIndex]);
replaceChildren
var changeIndex = 1; elements[changeIndex] = document.createElement('div'); container.replaceChildren(elements)
append documentFragment
var changeIndex = 1; var newChildren = document.createDocumentFragment(); elements[changeIndex] = document.createElement('div'); elements.forEach(element => newChildren.appendChild(element)); container.replaceChildren(newChildren)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replaceChild
replaceChildren
append documentFragment

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:126.0) Gecko/20100101 Firefox/126.0

Browser/OS: Firefox 126 on Windows

View result in a separate tab

Test name	Executions per second
replaceChild	1434729.0 Ops/sec
replaceChildren	575702.9 Ops/sec
append documentFragment	635970.6 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Goal**

The benchmark measures the performance difference between three approaches for replacing or appending child elements to an HTML container:

1. `replaceChild`
2. `replaceChildren`
3. Using a `documentFragment` to append children

**Options Compared**

Each option is compared in terms of execution speed (measured as executions per second).

### 1. replaceChild

`replaceChild` replaces the specified child element with a new one, and removes the old one from the DOM.

Pros:

* Simple and straightforward implementation
* Fast and efficient, since it only involves updating the DOM tree

Cons:

* May lead to unnecessary DOM reflows or repainting, especially if the replaced element has styles or attributes that need to be reapplied.
* Can result in a higher number of DOM mutations (i.e., changes to the DOM tree) compared to other options.

### 2. replaceChildren

`replaceChildren` replaces all child elements with a new set of children.

Pros:

* May reduce the number of DOM mutations, since it only involves replacing the existing children and adding new ones.
* Can be more efficient if the replaced children have similar structure or content.

Cons:

* May lead to slower performance if the replaced children are complex or have many attributes.
* Requires careful consideration of the new children's structure and content to ensure optimal performance.

### 3. Append documentFragment

Using a `documentFragment` to append children creates a new container element that holds all the child elements, which can then be appended to the parent element in one operation.

Pros:

* Reduces DOM mutations by creating a new container element.
* Can improve performance for large numbers of children or complex child elements.
* Allows for more control over the order and structure of the append operation.

Cons:

* Requires additional memory allocation for the `documentFragment` element.
* May lead to slower performance if the `documentFragment` is not properly optimized (e.g., by using an efficient fragment creation algorithm).

**Libraries Used**

None are explicitly mentioned in the provided benchmark definition. However, it's worth noting that some implementations of `replaceChild` and `replaceChildren` might rely on external libraries or frameworks for DOM manipulation.

**Special JS Features/Syntax**

There is no special JavaScript feature or syntax used in this benchmark. The code is standard JavaScript, with no references to advanced features like async/await, promises, or modern ES6+ syntax.

**Other Alternatives**

Some alternative approaches to replacing or appending child elements include:

* Using `insertBefore` or `insertAfter` instead of `replaceChild`
* Creating a new container element and appending the children manually
* Using a library like jQuery for DOM manipulation (although this is not explicitly mentioned in the benchmark definition)

Keep in mind that these alternatives might have different performance characteristics, trade-offs, or use cases compared to the options being tested in this benchmark.

Related benchmarks:

replaceChild vs replaceChildren vs documentFragment 2 (version: 0)

Comparing performance of: replaceChild vs replaceChildren vs append documentFragment

Created: 3 years ago by: Guest

Jump to the latest result

replaceChild

replaceChildren

append documentFragment

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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