Benchmark: My Comparison - MeasureThat.net

HTML Preparation code:

<div id="column-3" class="column-3"></div>

Tests:

querySelector
document.querySelector('#column-3');
getElementById
document.getElementById('column-3')
querySelectorAll
document.querySelectorAll('column-3')[0]
getElementsByClassName
document.getElementsByClassName('column-3')[0]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
querySelector
getElementById
querySelectorAll
getElementsByClassName

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

Browser/OS: Chrome 81 on Windows

View result in a separate tab

Test name	Executions per second
querySelector	2002564.8 Ops/sec
getElementById	3452720.5 Ops/sec
querySelectorAll	922740.4 Ops/sec
getElementsByClassName	2554076.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what is tested in the provided JSON, and I'll explain the options being compared, their pros and cons, and other considerations.

**Script Preparation Code**

The script preparation code is empty, which means that no special setup or imports are required to run the benchmarks. This makes it easier to compare different implementations, as we don't need to worry about the overhead of importing libraries or setting up environments.

**Individual Test Cases**

There are four test cases:

1. `querySelector`
2. `getElementById`
3. `querySelectorAll`
4. `getElementsByClassName`

These tests aim to measure the performance of different DOM query methods in JavaScript.

**Options being compared**

The options being compared are:

* `document.querySelector('#column-3');`
* `document.getElementById('column-3')`
* `document.querySelectorAll('column-3')[0]`
* `document.getElementsByClassName('column-3')[0]`

These methods are all used to retrieve an element from the DOM, but they differ in their syntax and behavior:

* `querySelector` is a more modern method that returns the first matching element or null if no match is found.
* `getElementById` is an older method that returns the element with the specified ID. If no element is found, it returns null.
* `querySelectorAll` returns a NodeList containing all matching elements. In this case, we're indexing into the array to get the first element.
* `getElementsByClassName` returns a NodeList containing all elements with the specified class name. Like `querySelectorAll`, we're indexing into the array to get the first element.

**Pros and Cons of each approach**

Here's a brief summary:

* `querySelector` is generally faster than the other methods, as it uses a more efficient algorithm and can return early if no match is found.
* `getElementById` is slower than `querySelector`, but may be preferred for older browsers or specific use cases where ID-based selection is necessary.
* `querySelectorAll` is slower than both `querySelector` and `getElementById` because it returns an entire NodeList, which requires more work to process.
* `getElementsByClassName` is similar to `querySelectorAll` in that it returns a NodeList, but may be faster for certain use cases where class-based selection is common.

**Library usage**

None of the test cases use any external libraries. They rely solely on the built-in DOM APIs provided by modern browsers.

**Special JS features or syntax**

There are no special JavaScript features or syntax used in these tests. The tests are straightforward and aim to measure the performance of simple DOM query methods.

**Other alternatives**

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

* Use `querySelector` with a CSS selector that is more efficient than using an ID-based selector.
* Implement your own custom DOM query method using techniques like regular expressions or array manipulations.
* Test the performance of different caching strategies for frequent DOM queries.

Keep in mind that these alternatives may introduce additional complexity and may not be relevant to the specific use case being tested.

Related benchmarks:

My Comparison (version: 0)

Comparing performance of: querySelector vs getElementById vs querySelectorAll vs getElementsByClassName

Created: 4 years ago by: Guest

Jump to the latest result

querySelector

getElementById

querySelectorAll

getElementsByClassName

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):