Benchmark: getElementById, querySelector, window

HTML Preparation code:

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

Tests:

getElementById
document.getElementById("test");
querySelector
document.querySelector("#test")
window
window["test"]
test
test

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById
querySelector
window
test

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/605.1.15 (KHTML, like Gecko) Version/15.3 Safari/605.1.15

Browser/OS: Safari 15 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
getElementById	9625799.0 Ops/sec
querySelector	6303459.0 Ops/sec
window	6840357.0 Ops/sec
test	9297106.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON benchmark.

**Benchmark Definition**

The benchmark definition represents the test cases to be run. In this case, we have four test cases:

1. `getElementById`: Tests the performance of `document.getElementById()` with a specific ID (`#test`).
2. `querySelector`: Tests the performance of `document.querySelector()` with a CSS selector (`#test`).
3. `window`: Tests the performance of accessing a property on the global `window` object using bracket notation (`window["test"]`).
4. `test`: This is an invalid test case, as it's trying to access a non-existent variable.

**Options Compared**

The benchmark is comparing different approaches to access elements or values in the HTML document:

* `document.getElementById()`
* `document.querySelector()` (a more modern and flexible alternative to `getElementById`)
* `window["test"]` (bracket notation on the global `window` object)

Each test case is designed to measure the performance of a specific approach.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **`document.getElementById()`**:
	* Pros: Simple, widely supported, and easy to use.
	* Cons: Can be slower than `querySelector` due to the need to traverse the DOM tree.
2. **`document.querySelector()`**:
	* Pros: More flexible and powerful than `getElementById`, as it allows for CSS selectors that can match elements with multiple attributes.
	* Cons: May require more browser versions support, as CSS selectors are more complex.
3. **`window["test"]```**:
	* Pros: Very simple and lightweight, as it only accesses a property on the global `window` object.
	* Cons: Limited flexibility and not suitable for accessing elements or values in the DOM.

**Library Usage**

There is no explicit library usage mentioned in the benchmark definition. However, note that `document.querySelector()` uses CSS selectors, which rely on a library of CSS rules. While this doesn't directly involve a JavaScript library, it's an important consideration when writing benchmarks.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes being used in these test cases. The benchmark focuses solely on the performance of accessing elements and values using different approaches.

**Alternatives**

If you were to create your own JavaScript microbenchmarking tool, here are some alternatives to consider:

* Instead of `document.getElementById()`, you could also use `document.querySelector()` with a more complex CSS selector.
* For testing string manipulation, you might use libraries like `lodash` or `underscore`.
* For testing performance in specific browser versions or architectures, you could use tools like Google Chrome DevTools' Performance Tab.

Keep in mind that the choice of alternatives depends on your specific use case and requirements.

Related benchmarks:

getElementById, querySelector, window (version: 0)

Comparing performance of: getElementById vs querySelector vs window vs test

Created: 6 years ago by: Guest

Jump to the latest result

getElementById

querySelector

window

test

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):