Benchmark: getComputedStyle vs clientWidth

HTML Preparation code:


<div id='test'></div>
<style>
  #test {
  	width: 100px;
  	height: 100px;
  	backgroundColor: black;
  }
</style>

Tests:

getComputedStyle
let style = getComputedStyle(document.getElementById("test")); let width = parseInt(style).width; let height = parseInt(style).height;
clientWidth
let container = document.getElementById("test"); let width = container.clientWidth; let height = container.clientHeight;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getComputedStyle
clientWidth

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.107 Safari/537.36 Edg/92.0.902.55

Browser/OS: Chrome 92 on Windows

View result in a separate tab

Test name	Executions per second
getComputedStyle	184881.1 Ops/sec
clientWidth	212067.9 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a JavaScript microbenchmark test case for comparing two methods to retrieve an element's width and height: `getComputedStyle` and `clientWidth`. The benchmark aims to determine which method is more efficient in terms of performance.

**Options Comparison**

There are three options compared:

1. **`getComputedStyle(element)`**: This method retrieves the computed style of a given DOM element.
2. **`element.clientWidth` (and `element.clientHeight` for height)**: These properties return the width and height of an element, respectively.
3. **No difference (i.e., no baseline)**: The benchmark asks whether there's any significant difference between these two approaches.

**Pros and Cons**

1. **`getComputedStyle(element)`**:
	* Pros:
		+ Retrieves accurate style information, including layout and positioning.
		+ May be necessary for complex CSS calculations or animations.
	* Cons:
		+ Can be slower due to the overhead of getting style information from the DOM.
		+ May require more memory allocation and garbage collection.
2. **`element.clientWidth` (and `element.clientHeight`)**:
	* Pros:
		+ Generally faster than `getComputedStyle(element)` since it only needs to access a property.
		+ Less memory allocation and garbage collection compared to `getComputedStyle`.
	* Cons:
		+ May not provide accurate results for elements with complex layouts or CSS rules.

**Library Usage**

None of the options use any specific JavaScript libraries. However, the benchmark does rely on the `document` object, which is a part of the DOM API.

**Special JS Features/Syntax (none)**

There are no special JavaScript features or syntax used in this benchmark.

**Other Alternatives**

If you want to compare these methods with other approaches, consider the following:

1. **Using the `getBoundingClientRect()` method**: This method returns an object containing the element's bounding rectangle, including width and height.
2. **Accessing CSS styles via `window.getComputedStyle()` (IE8-)**: This method is specific to Internet Explorer 8 and earlier versions. It retrieves the computed style of a given DOM element.

Keep in mind that these alternatives might have different performance characteristics or requirements compared to `getComputedStyle(element)` and `element.clientWidth`.

Related benchmarks:

getComputedStyle vs clientWidth (version: 7)

if one time get style. Better element.clientWidth if two - no difference if three ore more, Better getComputedStyle(element)

Comparing performance of: getComputedStyle vs clientWidth

Created: one year ago by: Registered User

Jump to the latest result

getComputedStyle

clientWidth

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):