Benchmark: queryselector vs getelementbyid multiple id

HTML Preparation code:

<div id="testElement"></div>
<div id="testElementTwo"></div>
<div id="testElementThree"></div>
<div id="testElementFour"></div>
<div id="testElementFive"></div>

Tests:

queryselector
var el = document.querySelector('#testElement'); var className = el.className;
getelementbyid
var el = document.getElementById('testElementFive'); var className = el.className;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
queryselector
getelementbyid

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Overview**

The provided benchmark compares two approaches for selecting elements in an HTML document: `querySelector` and `getElementById`. Specifically, it tests how fast these two methods can retrieve the class name of an element with a unique ID (`testElementFive`).

**Options Compared**

There are only two options being compared:

1. **`querySelector`**: This method uses CSS selectors to select elements. In this case, it's used to select `#testElementFive`.
2. **`getElementById`**: This method uses the `id` attribute of an element to identify and retrieve it.

**Pros and Cons**

**`querySelector`**

Pros:

* More flexible and powerful than `getElementById`, as it can be used to select elements based on various CSS selectors.
* Can be more efficient for larger, complex documents.

Cons:

* May be slower than `getElementById` due to the overhead of parsing CSS selectors.
* Requires a compatible browser that supports CSS selectors (most modern browsers do).

**`getElementById`**

Pros:

* Faster and more lightweight compared to `querySelector`.
* Works in older browsers that don't support CSS selectors.

Cons:

* Less flexible and powerful than `querySelector`, as it only selects elements by their ID.
* May be less efficient for larger documents.

**Other Considerations**

In this specific benchmark, the use of a unique ID (`testElementFive`) ensures that both methods are selecting the same element. However, in real-world scenarios, you might encounter cases where multiple elements have the same `id` attribute, or where you need to select elements based on different attributes.

**Library and Purpose**

In this benchmark, no external libraries are used. Both methods rely on the built-in JavaScript APIs of modern browsers.

However, if you were to implement a similar benchmark for other element selection methods, you might consider using libraries like `jQuery` or `DOMParser`, which provide more flexible and powerful ways to select elements in HTML documents.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax used in this benchmark. The focus is solely on comparing two established element selection methods.

**Alternative Approaches**

Other approaches for selecting elements include:

1. **`getContextById`**: This method is similar to `getElementById`, but it uses the `id` attribute of an HTML element to get a reference to its corresponding DocumentFragment.
2. **`querySelectorAll`**: While not exactly equivalent to `querySelector`, this method can be used to select multiple elements that match a CSS selector, which might be useful in certain scenarios.

Keep in mind that these alternative approaches might not provide the same performance characteristics as `querySelector` and `getElementById`, so it's essential to consider your specific use case and requirements when choosing an element selection method.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Linux

View result in a separate tab

Test name	Executions per second
queryselector	4589852.5 Ops/sec
getelementbyid	8136303.0 Ops/sec

Related benchmarks:

queryselector vs getelementbyid multiple id (version: 0)

Comparing performance of: queryselector vs getelementbyid

Created: 3 months ago by: Guest

Jump to the latest result

queryselector

getelementbyid

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):