Benchmark: getElementById, querySelector, windowqsd

HTML Preparation code:

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

Tests:

getElementById
document.getElementById("test");
querySelector
document.querySelector("#test")
window
test

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById
querySelector
window

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Browser/OS: Firefox 87 on Ubuntu

View result in a separate tab

Test name	Executions per second
getElementById	5269244.5 Ops/sec
querySelector	2691813.8 Ops/sec
window	1065631.6 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated 2 months ago):

LLMs can make mistakes. Check important info.

This benchmark compares three different methods for retrieving an element from an HTML document:

**1. `getElementById`:**  This method takes the ID of an element as input and returns the first element with that ID. It's straightforward and efficient when you know the exact ID of the element you need.

* **Pros:** 
    * Fast because it relies on a direct lookup by ID, which is a unique identifier for each element.

* **Cons:**
    * Only works if the target element has a unique ID attribute set. If multiple elements share an ID, it will only return the first one encountered.

**2. `querySelector`:** This method uses CSS selectors to search for an element in the document. It's more flexible than `getElementById` because you can use various CSS selectors to target elements based on attributes, classes, or even their position within the DOM tree.

* **Pros:**
    * More versatile due to its ability to use CSS selectors. This allows you to select multiple elements, target elements by class name, or even apply complex selection criteria.

* **Cons:**
    *  Can be slightly slower than `getElementById` in simple cases because it involves parsing the CSS selector and traversing the DOM tree. However, for more complex selections, it's often faster than repeatedly using `getElementById`.

**3. `window`:** This method seems out of place. The provided definition "test" doesn't actually interact with the document or elements.  It likely represents a placeholder or an error in the benchmark setup.

**Alternatives:**

* **Libraries like jQuery:** While not directly compared in this benchmark, libraries like jQuery often offer simplified and optimized methods for DOM manipulation, including element selection. They can abstract away some of the complexity and potentially improve performance.
* **Direct access with `Array.prototype` (for simple cases):** If you know the exact index of the element within a parent node's children, you could directly access it using array indexing (`parentNode.children[index]`), which might be faster than any of the mentioned methods in very specific scenarios.

Let me know if you have any other questions!

Related benchmarks:

getElementById, querySelector, windowqsd (version: 0)

Comparing performance of: getElementById vs querySelector vs window

Created: 3 years ago by: Guest

Jump to the latest result

getElementById

querySelector

window

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated 2 months ago):