Benchmark: clientHeight vs getComputedStyle().height

HTML Preparation code:

<div id="test">test</div>

Script Preparation code:

var element = document.getElementById('test');

Tests:

clientHeight
element.clientHeight;
getComputedStyle
parseFloat(window.getComputedStyle(element).height);

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

clientHeight

1.9M/s

getComputedStyle

913K/s

Fastest: clientHeight (2.1x faster)

View exact numbers

✓ clientHeight: 1,884,350 ops/sec
• getComputedStyle: 912,753 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
clientHeight
getComputedStyle

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0

Browser/OS: Firefox 147 on Windows

View result in a separate tab

clientHeight

29.4M/s

getComputedStyle

2.4M/s

View exact numbers

Test name	Executions per second
✓ clientHeight	29,352,466 Ops/sec
getComputedStyle	2,394,984 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark test case and explain what's being tested.

**What is being tested?**

The benchmark is comparing two approaches to retrieve the height of an HTML element:

1. `element.clientHeight`: This is a direct access to the client height property of the element. It returns the height of the visible part of the element, not including any padding or border.
2. `parseFloat(window.getComputedStyle(element).height)`: This uses the `getComputedStyle()` method to retrieve the computed style of the element and then parses the `height` property as a float.

**Options compared**

The two options are being compared in terms of their performance:

* `clientHeight` (Option 1)
* `getComputedStyle().height` (Option 2)

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

* **clientHeight**
	+ Pros: Direct access to client height, likely faster since it doesn't involve parsing or getting computed styles.
	+ Cons: May not include padding or border in the measurement, which could be important depending on the use case.
* `getComputedStyle().height`
	+ Pros: Includes padding and border in the measurement, providing a more comprehensive view of the element's height.
	+ Cons: Slower since it involves getting computed styles, parsing, and accessing properties.

**Library and purpose**

In this benchmark, the `getComputedStyle()` method is used to retrieve the computed style of an element. This library is part of the W3C DOM API and provides a way to access an element's styles without having to use CSS selectors or inline styles.

**Special JS feature or syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark. The code is straightforward and uses standard JavaScript methods and properties.

**Other alternatives**

Some alternative approaches to measuring an element's height could include:

* Using CSS selectors, such as `element.offsetHeight` (which includes padding and border) or `element.style.height`
* Using a library like jQuery that provides an `offset()` method for accessing an element's position and size
* Using a CSS grid system or layout engine to measure the height of elements

Overall, this benchmark is testing two common approaches to measuring an HTML element's height in JavaScript, highlighting their pros and cons, and providing insights into the performance differences between them.

clientHeight vs getComputedStyle().height (version: 0)

element.clientHeight vs window.getComputedStyle(element).height

Comparing performance of: `clientHeight vs getComputedStyle`

Created: 5 years ago by: Guest

Go to the latest result

clientHeight

getComputedStyle

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

clientHeight vs getComputedStyle().height (version: 0)

element.clientHeight vs window.getComputedStyle(element).height

Comparing performance of: clientHeight vs getComputedStyle

Created: 5 years ago by: Guest

Go to the latest result

clientHeight

getComputedStyle

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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Comparing performance of: `clientHeight vs getComputedStyle`