Toggle navigation
MeasureThat
.net
Create a benchmark
Tools
Feedback
FAQ
Register
Log In
getElementById vs querySelector, with two elements
(version: 0)
Comparing performance of:
getElementById vs querySelector
Created:
2 years ago
by:
Guest
Go to the latest result
HTML Preparation code:
<div id="testElement"></div> <div id="secondTestElement"></div>
Tests:
getElementById
var el = document.getElementById('testElement'); var className = el.className;
querySelector
var el = document.querySelector('#testElement'); var className = el.className;
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
Fork
Test case name
Result
getElementById
querySelector
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
2 years ago
)
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
Browser/OS:
Chrome 120 on Mac OS X 10.15.7
View result in a separate tab
Embed
Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=495969" width="100%" height="500px"></iframe>
getElementById
5.2M/s
querySelector
2.7M/s
View exact numbers
Test name
Executions per second
✓
getElementById
5,186,238 Ops/sec
querySelector
2,651,114 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the provided benchmark JSON and explain what is tested, compared, and their pros/cons. **Benchmark Definition** The benchmark tests two different ways to retrieve an HTML element by its ID: `document.getElementById` and `document.querySelector`. Both methods are used to access an element with the id "testElement" that appears twice in the prepared HTML code. **Options Compared** Two options are compared: 1. **`document.getElementById('testElement')`**: This method uses a traditional DOM-based approach to retrieve an element by its ID. 2. **`document.querySelector('#testElement')`**: This method uses CSS selectors to retrieve an element that matches the specified selector. **Pros and Cons** **`document.getElementById('testElement')`** Pros: * Well-established, widely supported, and easy to use. * Provides direct access to the DOM node. Cons: * Can be slower due to the need to traverse the DOM tree. * May have limitations when dealing with complex or dynamic elements. **`document.querySelector('#testElement')`** Pros: * More flexible and powerful than `getElementById`, allowing for more complex selectors. * Can reduce the need for explicit DOM manipulation. Cons: * Less widely supported, especially in older browsers. * May require additional setup or libraries to work correctly. **Library: CSSOM (CSS Object Model)** The `document.querySelector` method uses the CSS Object Model (CSSOM), which allows for the selection of elements based on their CSS styles. The CSSOM is a powerful tool that enables developers to write more flexible and efficient code. **Other Considerations** When choosing between these two approaches, consider the following: * If you need to retrieve an element by its ID in a simple or legacy application, `document.getElementById` might be a better choice due to its widespread support. * For more complex or dynamic applications, `document.querySelector` with CSS selectors can provide more flexibility and power. **Alternatives** If you're interested in exploring other alternatives, consider the following: * **`document.querySelectorAll('#testElement')`**: This method returns an array of elements that match the specified selector. It's similar to `querySelector`, but instead of returning a single element, it returns multiple elements. * **`Element.prototype.querySelector`**: Some modern browsers and libraries provide this method on the `Element` prototype, allowing for more flexible CSS selector usage. In summary, the benchmark tests two common ways to retrieve an HTML element by its ID in JavaScript: traditional DOM-based `document.getElementById` and CSS-based `document.querySelector`. While both methods have their pros and cons, `document.querySelector` with CSS selectors offers more flexibility and power, but may require additional setup or libraries for older browsers.
Related benchmarks
querySelector vs getElementById
querySelector vs getElementById & getElementsByClassName
getElementById vs querySelector 2
Comments
Confirm delete:
Do you really want to delete benchmark?