Benchmark: elem.ownerDocument.defaultView.getComputedStyle vs window.getComputedStyle

HTML Preparation code:

<div id="root"><div>

Script Preparation code:

var el = document.getElementById("root");
function getStyle(elem){
  return elem.ownerDocument.defaultView.getComputedStyle( elem );
}

function getStyle2(elem){
  return window.getComputedStyle( elem );
}

Tests:

ownerDocument.defaultView
var computedStyle = getStyle(el);
window.getComputedStyle
var computedStyle = getStyle2(el);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
ownerDocument.defaultView
window.getComputedStyle

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the benchmark being measured on MeasureThat.net.

**What is being tested?**

The benchmark is comparing two approaches to access the computed style of an element:

1. `elem.ownerDocument.defaultView.getComputedStyle(elem)`
2. `window.getComputedStyle(elem)`

These two approaches are testing how efficient and accurate each method is in retrieving the computed style of an element, which includes properties like width, height, color, etc.

**Options compared:**

There are two options being compared:

A) Using the `ownerDocument.defaultView` object to access the global CSSOM (CSS Object Model) API.
B) Using the `window.getComputedStyle()` method directly on the window object.

**Pros and Cons of each approach:**

1. **Using `elem.ownerDocument.defaultView.getComputedStyle(elem)`**
	* Pros:
		+ More direct and native access to the CSSOM API, which can be more efficient.
		+ Can provide better accuracy in terms of handling complex style inheritance scenarios.
	* Cons:
		+ Requires accessing the `ownerDocument` property on the element, which may introduce additional overhead or dependencies.
2. **Using `window.getComputedStyle(elem)`**
	* Pros:
		+ More straightforward and widely supported method, as it doesn't require access to the `ownerDocument` property.
		+ May be easier to implement and maintain for developers who are not familiar with the CSSOM API.
	* Cons:
		+ Can be less efficient due to additional overhead or dependencies introduced by accessing the window object.

**Library/Tool usage:**

There is no specific library being used in this benchmark, but it relies on the JavaScript Engine and Browser implementations of the `getComputedStyle()` method. The `ownerDocument` property is a part of the DOM (Document Object Model) API, which is implemented natively by most browsers.

**Special JS feature or syntax:**

There are no special JS features or syntax being used in this benchmark beyond standard ECMAScript 2020 language features.

**Other alternatives:**

Some alternative approaches to accessing the computed style of an element include:

* Using the `getComputedStyle()` method on a separate CSSStyleRule object, if available.
* Implementing a custom solution using DOM manipulation and CSS selectors.
* Utilizing browser-specific APIs or extensions (e.g., React Query or other optimization libraries).

Keep in mind that these alternatives may have different performance implications, trade-offs, or requirements depending on the specific use case.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.102 Safari/537.36

Browser/OS: Chrome 104 on Windows

View result in a separate tab

Test name	Executions per second
ownerDocument.defaultView	1899320.9 Ops/sec
window.getComputedStyle	1618832.6 Ops/sec

Related benchmarks:

elem.ownerDocument.defaultView.getComputedStyle vs window.getComputedStyle (version: 0)

Comparing performance of: ownerDocument.defaultView vs window.getComputedStyle

Created: 2 years ago by: Guest

Jump to the latest result

ownerDocument.defaultView

window.getComputedStyle

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):