Benchmark: getElementById vs querySelector vs querySelector for some other attribute vs querySelectorAll for some other attribute

HTML Preparation code:

<div id="testElement" at="testElement"></div>

Tests:

getElementById
var el = document.getElementById('testElement'); var className = el.className;
querySelector
var el = document.querySelector('#testElement'); var className = el.className;
querySelector for some other attribute
var el = document.querySelector('[at="testElement"]'); var className = el.className;
querySelectorAll for some other attribute
var el = document.querySelectorAll('[at="testElement"]'); var className = el[0].className;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById
querySelector
querySelector for some other attribute
querySelectorAll for some other attribute

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript benchmarks.

**Benchmark Overview**

The provided benchmark measures the performance of four different approaches to selecting an HTML element:

1. `document.getElementById`
2. `document.querySelector`
3. `document.querySelector` with an additional attribute (`[at="testElement"]`)
4. `document.querySelectorAll` with an additional attribute (`[at="testElement"]`)

**Options Compared**

Each option is compared in terms of their execution speed, measured in executions per second (EPS). The benchmark runs each test case multiple times to generate a large number of results, which are then used to calculate the average EPS for each option.

**Approaches and Their Pros and Cons**

1. **`document.getElementById`**: This method is simple and widely supported, but it can be slower than other options because it uses a more invasive approach to find an element by its ID.
	* Pros: Wide support, easy to use
	* Cons: May be slower due to the invasive nature of the search
2. **`document.querySelector`**: This method is faster and more flexible than `getElementById`, but it requires a CSS selector to find the element.
	* Pros: Faster, more flexible
	* Cons: Requires CSS knowledge to set up the selector
3. **`document.querySelector` with an additional attribute (`[at="testElement"]`)**: This method is similar to `querySelector`, but uses an additional attribute to narrow down the search results.
	* Pros: Faster than `getElementById`, easier to use than `querySelector` without attribute
	* Cons: Requires some knowledge of CSS and JavaScript attributes
4. **`document.querySelectorAll` with an additional attribute (`[at="testElement"]`)**: This method is similar to `querySelectorAll`, but only returns the first match instead of all matches.
	* Pros: Faster than `querySelector`, easier to use than `querySelectorAll`
	* Cons: Returns a single element, not all matching elements

**Library and Purpose**

The benchmark uses the W3C CSS Selectors specification as its basis for the `document.querySelector` and `document.querySelectorAll` methods. These specifications define how CSS selectors can be used to select elements in an HTML document.

**Special JS Feature or Syntax (None)**

There are no special JavaScript features or syntaxes being tested in this benchmark. The focus is on comparing different approaches to selecting an element using standard JavaScript APIs.

**Other Alternatives**

If you need a more comprehensive benchmarking platform, you might consider alternatives like:

1. **Benchmark.js**: A popular JavaScript benchmarking library that provides a simple and efficient way to create benchmarks.
2. **jsPerf**: A tool for running JavaScript performance tests and comparing the results.
3. **Benchmarking frameworks** like Benchmark, Fastbench, or JSBench, which provide more advanced features and tools for creating and running benchmarks.

Keep in mind that each alternative has its own strengths and weaknesses, so it's essential to choose the one that best fits your specific needs.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0

Browser/OS: Firefox 91 on Ubuntu

View result in a separate tab

Test name	Executions per second
getElementById	4646172.0 Ops/sec
querySelector	3148892.8 Ops/sec
querySelector for some other attribute	1719002.4 Ops/sec
querySelectorAll for some other attribute	842650.2 Ops/sec

Related benchmarks:

getElementById vs querySelector vs querySelector for some other attribute vs querySelectorAll for some other attribute (version: 0)

Comparing performance of: getElementById vs querySelector vs querySelector for some other attribute vs querySelectorAll for some other attribute

Created: 4 years ago by: Guest

Jump to the latest result

getElementById

querySelector

querySelector for some other attribute

querySelectorAll for some other attribute

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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