Benchmark: window.getComputedStyle vs document.getElementById.getAttribute

HTML Preparation code:

<div id="foo" data-attr="foo" style="transform: translate3d(0, -350px, 0)"></div>

Tests:

getComputedStyle
var i = 3000; while (i--) { chekele('foo'); } function chekele(element) { var tr = window.getComputedStyle(document.getElementById(element), null).getPropertyValue("transform"); return tr; }
getAttribute
var i = 3000; while (i--) { chekele('foo'); } function chekele(element) { return document.getElementById(element).getAttribute('data-attr'); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getComputedStyle
getAttribute

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
getComputedStyle	248.5 Ops/sec
getAttribute	8597.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the provided benchmark and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Definition**

The benchmark is designed to compare two approaches for retrieving the `transform` property from an HTML element:

1. Using `window.getComputedStyle(document.getElementById(element), null).getPropertyValue("transform")`
2. Using `document.getElementById(element).getAttribute('data-attr')`

Both methods aim to retrieve the same value, but they differ in how they achieve it.

**Test Case 1: getComputedStyle**

The first test case uses the `getComputedStyle` method to retrieve the `transform` property from an element with the id "foo". This method returns a string representing the computed style of the element, including the `transform` property.

**Pros:**

* This approach is more precise, as it retrieves the exact computed value.
* It's a standard method in JavaScript and widely supported by browsers.

**Cons:**

* It can be slower than other approaches, especially for elements with complex styles or animations.
* It requires additional DOM queries to retrieve the element, which might incur performance overhead.

**Test Case 2: getAttribute**

The second test case uses the `getAttribute` method to retrieve the value of the `data-attr` attribute from the same element. This approach is simpler and more lightweight than `getComputedStyle`.

**Pros:**

* It's faster and more lightweight, as it only retrieves a single attribute value.
* It doesn't require additional DOM queries or style computations.

**Cons:**

* It might not return the exact computed value, as it relies on the attribute value being set to a string representation of the transform property. This can lead to discrepancies between the retrieved value and the actual computed value.
* It's less precise than `getComputedStyle`, which returns a complete style object.

**Library/Language Features Used**

In this benchmark, no specific JavaScript library or framework is used beyond the standard DOM API. However, it's worth noting that some browsers may use proprietary extensions to their engine (e.g., WebKit) for certain tasks, such as CSS computations.

**Special JS Feature/Syntax**

This benchmark does not use any special JavaScript features or syntax. It focuses on comparing two common approaches to retrieving an attribute value from the DOM.

**Alternatives**

If you're interested in exploring alternative methods, here are a few options:

1. Using `requestAnimationFrame` with CSS animations: This approach can be faster than `getComputedStyle`, but it requires more complex setup and may not work for all cases.
2. Using Web Worker threads for parallel execution: This approach can significantly improve performance by executing the benchmark in parallel with other tasks, but it's more complex to implement and might require additional infrastructure.
3. Using a library like Fastdom or jsdom to simulate the DOM: These libraries provide an artificial DOM environment that allows you to run benchmarks in isolation from real-world rendering and layout issues.

Keep in mind that each alternative has its own trade-offs and requirements, and the choice of approach depends on your specific use case and performance goals.

Related benchmarks:

window.getComputedStyle vs document.getElementById.getAttribute (version: 0)

Comparing performance of: getComputedStyle vs getAttribute

Created: 2 years ago by: Guest

Jump to the latest result

getComputedStyle

getAttribute

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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