Benchmark: getElementById VS querySelector (simple comparison)

HTML Preparation code:

<div id="example"></div>

Tests:

The method getElementById()
document.getElementById("example");
The method querySelector()
document.querySelector("#example");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
The method getElementById()
The method querySelector()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36

Browser/OS: Chrome 145 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
The method getElementById()	51472640.0 Ops/sec
The method querySelector()	8065096.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript benchmarking.

**What is being tested?**

The provided JSON represents two test cases: `getElementById` and `querySelector`. The goal is to compare the performance between these two methods, which are both used to retrieve elements from a DOM (Document Object Model) in an HTML document.

**What options are compared?**

In this benchmark, two options are being compared:

1. **`document.getElementById()`**: This method retrieves an element by its ID using the `getById()` function.
2. **`document.querySelector()`**: This method retrieves an element that matches a specified CSS selector.

**Pros and Cons of each approach:**

1. **`document.getElementById()`**:
	* Pros:
		+ Simple and widely supported.
		+ Can be faster for simple, single-element retrievals.
	* Cons:
		+ May not be as efficient for more complex selections or large datasets.
		+ Can be less flexible than `querySelector`.
2. **`document.querySelector()`**:
	* Pros:
		+ More powerful and flexible, allowing for CSS selectors that can match multiple elements.
		+ Better suited for larger datasets or more complex selections.
	* Cons:
		+ May be slower due to the need to parse the CSS selector.
		+ Less widely supported in older browsers.

**Library usage:**

In this benchmark, there is no explicit library mentioned. However, `document.getElementById()` and `document.querySelector()` are built-in methods of the DOM API, which is part of the JavaScript language itself.

**Special JS features or syntax:**

There are no specific JavaScript features or syntax used in these benchmarks that would require special explanation.

**Other alternatives:**

If you're looking for alternative methods to retrieve elements from a DOM, consider using other APIs like:

* `document.querySelectorAll()` (similar to `querySelector()`, but returns all matching elements)
* `Element.getBoundingClientRect()` and related methods (for retrieving element bounds or position)
* `CSSOM` API (CSS Selectors API)

Keep in mind that the choice of method depends on your specific use case, performance requirements, and compatibility considerations.

I hope this explanation helps you understand what's being tested in this benchmark!

Related benchmarks:

getElementById VS querySelector (simple comparison) (version: 2)

A simple comparison of performance between these two methods. (Medium, @benlmsc)

Comparing performance of: The method getElementById() vs The method querySelector()

Created: 4 years ago by: Registered User

Jump to the latest result

The method getElementById()

The method querySelector()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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