Benchmark: document.getElementById, document.querySelector, element.querySelector

HTML Preparation code:

<header>Page header</header>
<nav>Navigation</nav>
<section id="content">
  <div id="nothing1"></div>
  <div id="nothing2"></div>
  <div id="nothing3"></div>
  <div id="container">
    <p><input id="testbutton" type="button" value="Test Button"></input></p>
  </div>
</section>
<footer>Page footer</footer>

Script Preparation code:

var container = document.getElementById("container");

Tests:

document.getElementById
document.getElementById("testbutton");
document.querySelector
document.querySelector("#testbutton");
element.querySelector
container.querySelector("#testbutton");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
document.getElementById
document.querySelector
element.querySelector

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Linux

View result in a separate tab

Test name	Executions per second
document.getElementById	6272103.0 Ops/sec
document.querySelector	2674465.8 Ops/sec
element.querySelector	6882864.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, the different approaches compared, their pros and cons, and other considerations.

**Benchmark Overview**

The test cases are designed to measure the performance of three ways to select an HTML element:

1. `document.getElementById("testbutton")`
2. `document.querySelector("#testbutton")`
3. `container.querySelector("#testbutton")`

where `container` is a previously created element with the id "container".

**Library and Special Features**

The test cases use JavaScript's DOM (Document Object Model) APIs, specifically:

* `document.getElementById()`: a method of the `document` object that returns the HTML element identified by the specified ID.
* `document.querySelector()` and `container.querySelector()`: methods of the `document` and `container` objects respectively, that return the first element matching the specified selector.

The test cases do not use any special JavaScript features or syntax.

**Approaches Compared**

There are three approaches being compared:

1. **Direct DOM Access**: Using `document.getElementById()` to select the element directly.
2. **QuerySelector API**: Using `document.querySelector()` and `container.querySelector()` to select elements using a CSS-like selector.
3. **Container QuerySelector API**: Using `container.querySelector()` to select an element from a specific container.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Direct DOM Access**
	* Pros:
		+ Simple and straightforward
		+ Fast, as it involves direct access to the DOM object.
	* Cons:
		+ Less flexible, as it only works with IDs.
		+ May be slower than other approaches if the element is not found quickly.
2. **QuerySelector API**
	* Pros:
		+ More flexible than Direct DOM Access, supporting CSS-like selectors.
		+ Easier to read and maintain code.
	* Cons:
		+ May be slower than Direct DOM Access, as it involves more processing to find the element.
3. **Container QuerySelector API**
	* Pros:
		+ Similar flexibility to QuerySelector API
	* Cons:
		+ Less flexible than QuerySelector API, as it only works within a specific container.

**Other Considerations**

When choosing an approach, consider the following:

* The complexity of your HTML structure and the number of elements you need to select.
* The frequency of element updates or changes in the DOM.
* The importance of readability and maintainability in your code.
* The performance requirements of your application.

**Alternatives**

If you're looking for alternatives, here are a few options:

1. **CSS Selectors**: You can also use CSS selectors to select elements, which may be faster than JavaScript-based approaches. However, this approach requires knowledge of CSS selectors and may not work in all cases.
2. **Template Engines**: Some template engines, like Mustache or Handlebars, provide built-in support for DOM selection and manipulation. These engines may offer better performance and flexibility than traditional JavaScript approaches.
3. **UI Libraries**: Frameworks like React or Angular provide their own DOM selection and manipulation APIs, which may be more efficient and easier to use than traditional JavaScript methods.

In conclusion, the benchmark provides a good starting point for comparing the performance of different approaches for selecting HTML elements in JavaScript. By considering the pros and cons of each approach and other factors, you can choose the best method for your specific use case.

Related benchmarks:

document.getElementById, document.querySelector, element.querySelector (version: 0)

Comparing performance of: document.getElementById vs document.querySelector vs element.querySelector

Created: 6 years ago by: Registered User

Jump to the latest result

document.getElementById

document.querySelector

element.querySelector

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):