Benchmark: FIND SINGLE ELEMENT: querySelector(ID, TagName e Class) vs getElementsByClassName vs getElementsByID vs getElementsByTagName — (getElementsByClassName sem .(ponto))

FIND SINGLE ELEMENT: querySelector(ID, TagName e Class) vs getElementsByClassName vs getElementsByID vs getElementsByTagName — (getElementsByClassName sem .(ponto)) (version: 2)

Comparing performance of: querySelector (Class) vs getElementsByClassName vs querySelector (ID) vs getElementsByID vs getElementsByTagName vs querySelector (TagName)

Created: 5 years ago by: Registered User

Jump to the latest result

HTML Preparation code:

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

Tests:

querySelector (Class)
document.querySelector(".test")
getElementsByClassName
document.getElementsByClassName("test")[0]
querySelector (ID)
document.querySelector("#test")
getElementsByID
document.getElementById("test")
getElementsByTagName
document.getElementsByTagName("div")[0]
querySelector (TagName)
document.querySelector("div")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
querySelector (Class)
getElementsByClassName
querySelector (ID)
getElementsByID
getElementsByTagName
querySelector (TagName)

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided JSON represents a benchmark definition for comparing the performance of different DOM querying methods in JavaScript.

The benchmark consists of six test cases:

1. `querySelector(Class)`: Tests the performance of using `document.querySelector()` with a class selector.
2. `getElementsByClassName`: Tests the performance of using `document.getElementsByClassName()` to retrieve elements by their class names.
3. `querySelector(ID)`: Tests the performance of using `document.querySelector()` with an ID selector.
4. `getByIdClass`: Tests the performance of using `document.getElementById()` followed by a class query (not actually tested, see below).
5. `getElementsByTagName`: Tests the performance of using `document.getElementsByTagName()` to retrieve elements by their tag name.
6. `querySelector(TagName)`: Tests the performance of using `document.querySelector()` with a tag name selector.

**Comparison Options**

The benchmark compares the performance of four DOM querying methods:

1. `document.querySelector()`: A method that selects an element by its CSS selector or attribute.
2. `document.getElementsByClassName()`: A method that retrieves all elements with a given class name.
3. `document.getElementById()`: A method that retrieves the first element with a given ID.
4. `document.getElementsByTagName()`: A method that retrieves all elements of a given tag name.

**Pros and Cons**

* **`document.querySelector()`**: Pros:
	+ Flexible selector syntax (class, ID, tag name, attribute).
	+ Can be used to select multiple elements at once.
	+ Supports CSS selectors.
	Cons:
	+ May have slower performance compared to other methods for simple queries.
* `document.getElementsByClassName()`: Pros:
	+ Fast performance for retrieving all elements with a given class name.
	+ Simple and efficient syntax.
Cons:
	+ Returns all matching elements, which can be more memory-intensive than single-element selections.
* `document.getElementById()`: Pros:
	+ Very fast performance for retrieving the first element with a given ID.
	+ Simple and efficient syntax.
Cons:
	+ Only retrieves the first matching element, which may not match expectations in some cases.
* `document.getElementsByTagName()`: Pros:
	+ Fast performance for retrieving all elements of a given tag name.
	+ Simple and efficient syntax.
Cons:
	+ Returns all matching elements, which can be more memory-intensive than single-element selections.

**Library Use**

In the provided benchmark, none of the test cases use any external libraries. However, it's worth noting that some of these methods may rely on libraries or frameworks to achieve their full potential (e.g., using CSS selectors with `document.querySelector()`).

**Special JS Features/Syntax**

None of the test cases explicitly use special JavaScript features or syntax. However, it's worth noting that some of these methods may rely on specific browser implementations or engine optimizations to achieve optimal performance.

**Benchmark Preparation Code and HTML**

The benchmark preparation code is empty, indicating that no additional setup is required for each test case. The provided HTML code includes a single `<div>` element with the class `test` and ID `test`, which serves as the target element for each test case.

**Alternatives**

If you're looking for alternative methods or approaches to DOM querying in JavaScript, consider the following:

* Use libraries like jQuery (for compatibility and ease of use) or other DOM manipulation libraries.
* Implement custom query functions using techniques like XPath or CSS selectors.
* Consider using more modern JavaScript features, such as `querySelectorAll()` and `getElementsByClassName`, which offer improved performance and flexibility.

Keep in mind that the best approach depends on your specific use case and requirements. MeasureThat.net's benchmark can provide valuable insights into the relative performance of different DOM querying methods.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.125 Safari/537.36

Browser/OS: Chrome 84 on Windows

View result in a separate tab

Test name	Executions per second
querySelector (Class)	3322791.2 Ops/sec
getElementsByClassName	2567779.8 Ops/sec
querySelector (ID)	2381020.5 Ops/sec
getElementsByID	2925576.0 Ops/sec
getElementsByTagName	2450924.8 Ops/sec
querySelector (TagName)	2475596.2 Ops/sec

Related benchmarks:

FIND SINGLE ELEMENT: querySelector(ID, TagName e Class) vs getElementsByClassName vs getElementsByID vs getElementsByTagName — (getElementsByClassName sem .(ponto)) (version: 2)

Comparing performance of: querySelector (Class) vs getElementsByClassName vs querySelector (ID) vs getElementsByID vs getElementsByTagName vs querySelector (TagName)

Created: 5 years ago by: Registered User

Jump to the latest result

querySelector (Class)

getElementsByClassName

querySelector (ID)

getElementsByID

getElementsByTagName

querySelector (TagName)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):