Benchmark: getElementById, querySelectorAll

HTML Preparation code:

<div id="test">Test</div>

Tests:

getElementById
document.getElementById("test");
querySelector
document.querySelectorAll("#test")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById
querySelector

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.63 Safari/537.36 Edg/93.0.961.47

Browser/OS: Chrome 93 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
getElementById	4368869.5 Ops/sec
querySelector	1535827.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**What is being tested?**

The benchmark measures the performance of two JavaScript methods: `document.getElementById()` and `document.querySelectorAll()`. These methods are used to retrieve elements from an HTML document using their IDs or selectors, respectively.

**Options compared**

In this benchmark, two options are compared:

1. **`document.getElementById()`**: This method takes a string argument representing the ID of the element to be retrieved. It returns the first matching element in the document's DOM.
2. **`document.querySelectorAll()`**: This method takes a string argument representing the CSS selector(s) of the elements to be retrieved. It returns a NodeList containing all matching elements.

**Pros and Cons**

Here are some pros and cons of each approach:

* `document.getElementById()`:
	+ Pros: Simple, efficient, and well-supported.
	+ Cons: Only retrieves the first matching element, which might not be what you want if there are multiple matches. Also, it can be slower than `querySelectorAll()` for large datasets.
* `document.querySelectorAll()`: 
	+ Pros: Can retrieve multiple elements, more flexible, and faster than `getElementById()` for large datasets. However, it returns a NodeList, which might not be as convenient to work with as an individual element.
* Another option could be using modern JavaScript features like `Element.prototype.querySelector()` or `Array.from(elementList).filter()`, but they are not mentioned in the benchmark definition.

**Library usage**

In this benchmark, there is no explicit library used. However, the `document` object and its methods (`getElementById()`, `querySelectorAll()`) are part of the DOM (Document Object Model), which is a built-in API for working with HTML documents.

**Special JS features or syntax**

There are no special JavaScript features or syntax mentioned in the benchmark definition that would require additional explanation. However, it's worth noting that the use of ES6+ syntax like template literals (`"document.getElementById(\"test\")"` and `"document.querySelectorAll(\"#test\")")` is used, which is a relatively modern syntax introduced by ECMAScript 2015 (ES6).

**Other alternatives**

Some other alternatives to `document.getElementById()` and `document.querySelectorAll()` include:

* Using jQuery, a popular JavaScript library for working with HTML documents.
* Utilizing frameworks like React or Angular, which provide their own APIs for DOM manipulation.
* Implementing custom DOM traversal algorithms using vanilla JavaScript.

In summary, the benchmark measures the performance of two fundamental DOM methods: `document.getElementById()` and `document.querySelectorAll()`. The options compared are simple and well-supported, but also have trade-offs in terms of convenience and performance.

Related benchmarks:

getElementById, querySelectorAll (version: 0)

Comparing performance of: getElementById vs querySelector

Created: 6 years ago by: Guest

Jump to the latest result

getElementById

querySelector

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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