Toggle navigation
MeasureThat
.net
Create a benchmark
Tools
Feedback
FAQ
Register
Log In
querySelector vs getElementsByClassName My
(version: 0)
Comparing performance of:
querySelector vs getElementsByClassName
Created:
4 years ago
by:
Guest
Go to the latest result
HTML Preparation code:
<div class="test"></div>
Tests:
querySelector
document.querySelector(".test")
getElementsByClassName
document.getElementsByClassName(".test")[0]
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
Fork
Test case name
Result
querySelector
getElementsByClassName
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
one year ago
)
User agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36
Browser/OS:
Chrome 133 on Windows
View result in a separate tab
Embed
Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=593412" width="100%" height="500px"></iframe>
querySelector
9.3M/s
getElementsByClassName
5.2M/s
View exact numbers
Test name
Executions per second
✓
querySelector
9,306,032 Ops/sec
getElementsByClassName
5,172,568 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the provided JSON and explain what's being tested, compared, and some considerations. **Benchmark Definition** The benchmark defines two test cases: `querySelector` and `getElementsByClassName`. These are JavaScript methods used to select elements in HTML documents. **What is being tested?** * `document.querySelector('.test')`: This method selects the first element with the class `test`. * `document.getElementsByClassName('test')[0]`: This method returns an array of elements with the class `test` and returns the first element from that array. **Options compared** The benchmark is comparing two approaches to select elements: 1. **querySelector**: A modern, faster way to select elements using a CSS selector syntax. 2. **getElementsByClassName**: An older way to select elements by class name, which was the only method available before `querySelector` was introduced in modern browsers. **Pros and Cons** * **querySelector**: + Pros: Faster, more efficient, and widely supported across modern browsers. It's also more flexible than `getElementsByClassName`. + Cons: Requires CSS selectors to be used, which can add complexity. * **getElementsByClassName**: + Pros: Simpler to use and more forgiving for older browsers that don't support `querySelector`. It's also more flexible when dealing with elements without a class attribute. + Cons: Slower and less efficient than `querySelector`. **Library usage** In the benchmark, `document` is used as the root element of the HTML document. There are no external libraries being used. **Special JS features or syntax** There are none mentioned in this specific benchmark. However, it's worth noting that other benchmarks might use newer JavaScript features like async/await, Promises, or modern language constructs like arrow functions or destructuring. **Other alternatives** For selecting elements, you can also use other methods like: * `querySelectorAll`: Similar to `querySelector`, but returns a NodeList with all matching elements. * `document.querySelector~` and `document.querySelectorAll~`: These use a substring matching approach for partial matches. * Other libraries like jQuery or Vanilla-Extract. Keep in mind that the best method for your specific use case depends on factors like browser support, performance requirements, and complexity.
Related benchmarks
querySelector() vs getElementsByClassName()[0]
querySelector vs getElementsByClassName()[0]
getElementsByClassName()[0] vs querySelectorAll
querySelector vs getElementsByClassName [0] with extra
Comments
Confirm delete:
Do you really want to delete benchmark?