Benchmark: replaceChildren vs appendChild for empty container

HTML Preparation code:

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

Script Preparation code:

window.myChild = document.createElement("span");
window.myChild.innerText = "Benchmarking...";
window.theContainer = document.getElementById("container");

Tests:

replaceChildren
window.theContainer.replaceChildren(window.myChild);
appendChild
window.theContainer.appendChild(window.myChild);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replaceChildren
appendChild

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its options.

**Benchmark Definition**

The benchmark measures the performance difference between two approaches: `replaceChildren` and `appendChild` when used to replace the content of an empty container element.

**Options Compared**

1. **`replaceChildren`**: This method replaces all child nodes of the container element with a single new node, in this case, `window.myChild`. It's likely that the browser will need to traverse the DOM tree and update the element's children.
2. **`appendChild`**: This method adds a new node to the end of the container element's child list. To replace the content, you would typically append multiple nodes or use other methods like `innerHTML`.

**Pros and Cons**

*   **`replaceChildren`**:
    *   Pros: Can be faster since it only updates the DOM tree for the new node.
    *   Cons: May require more complex logic in JavaScript if the container has a large number of child nodes.
*   **`appendChild`**:
    *   Pros: Generally easier to implement and understand, especially when working with a small number of child nodes.
    *   Cons: Requires appending multiple nodes or using other methods like `innerHTML`, which can be slower.

**Library Usage**

None mentioned in the provided benchmark definition.

**Special JS Features/Syntax**

There is no special JavaScript feature or syntax used in this benchmark. It's a standard DOM manipulation scenario.

**Other Alternatives**

Alternative approaches to replace the content of an element:

*   **`innerHTML`**: This method replaces the entire HTML content of an element, which can be slower than using `replaceChildren` or `appendChild`.
*   **`slice()` and `splice()` methods**: These methods allow you to remove and replace elements from a container's child list.
*   **Template literals** (ES6+): You can use template literals to create a new element and then append it to the container using `appendChild`.

In conclusion, this benchmark compares two common DOM manipulation techniques: `replaceChildren` and `appendChild`. The choice between these methods depends on the specific requirements of your project and the number of child nodes involved.

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Windows

View result in a separate tab

Test name	Executions per second
replaceChildren	1582352.1 Ops/sec
appendChild	1825674.6 Ops/sec

Related benchmarks:

replaceChildren vs appendChild for empty container (version: 0)

Comparing performance of: replaceChildren vs appendChild

Created: 9 months ago by: Guest

Jump to the latest result

replaceChildren

appendChild

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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