Benchmark: querySelector on HTML tag vs. closest

HTML Preparation code:

<html>
  <body>
    <div>
      <div>
        <div>
          <div>
            <div id="test"></div>
          </div>
        </div>
      </div>
    </div>
  </body>
</html>

Script Preparation code:

window.theDiv = document.querySelector('#test');

Tests:

getting the html tag with querySelector
const theHtml = document.querySelector('html');
getting the html tag with closest
const theHtml = theDiv.closest('html')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getting the html tag with querySelector
getting the html tag with closest

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_1_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1.1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.1.1

View result in a separate tab

Test name	Executions per second
getting the html tag with querySelector	10972273.0 Ops/sec
getting the html tag with closest	6068134.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a JavaScript microbenchmark test case for measuring the performance of two different approaches: `querySelector` and `closest`.

**Options Compared**

The benchmark compares the execution time of two methods:

1. **querySelector**: A method used to select an element from the DOM using its id, class, or tag name.
2. **closest**: A method provided by the jQuery library (not explicitly mentioned in the JSON, but implied) that returns the closest ancestor element matching a given selector.

**Pros and Cons**

* **querySelector**:
	+ Pros: Widely supported by most browsers, easy to use, and provides a simple way to select elements.
	+ Cons: Can be slower than `closest` for complex selections or deep DOM structures.
* **closest** (assuming jQuery is used):
	+ Pros: Can be faster than `querySelector` for certain types of selections, especially when dealing with complex DOM structures.
	+ Cons: Requires jQuery library to be included and may have a smaller user base compared to `querySelector`.

**Library Consideration**

The test case uses the `document.querySelector` method, which is a standard DOM API method. However, it's worth noting that some browsers (e.g., Internet Explorer) do not support this method and may use alternative methods instead.

There is no explicit mention of jQuery in the provided JSON, but if it were used for the `closest` approach, the benefits mentioned above would apply.

**Special JS Feature or Syntax**

None are explicitly mentioned in the test case. However, if we were to consider other JavaScript features or syntax, some examples might include:

* Using `document.querySelector` with a CSS selector (e.g., `#test > *`)
* Utilizing browser-specific APIs (e.g., WebKit's `querySelector` implementation has some differences from the standard DOM API)
* Leveraging modern JavaScript features like async/await or promises

**Other Alternatives**

If you were to write a similar benchmark, you might consider adding additional test cases for:

* Using `document.getElementById` instead of `querySelector`
* Utilizing other methods for selecting elements, such as `getElementsByTagName` or `getElementsByClassName`
* Comparing performance with different DOM tree structures or sizes
* Testing the impact of various browser-specific optimizations (e.g., Chrome's V8 engine) on performance

Keep in mind that these alternatives would require additional test cases and modifications to the existing benchmark code.

Related benchmarks:

querySelector on HTML tag vs. closest (version: 0)

Figuring out what's faster, to querySelect the HTML tag or use the javascript closest

Comparing performance of: getting the html tag with querySelector vs getting the html tag with closest

Created: 4 years ago by: Guest

Jump to the latest result

getting the html tag with querySelector

getting the html tag with closest

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):