Benchmark: test456 - MeasureThat.net

HTML Preparation code:

<div id="div"></div>

Tests:

getElementById
let q = document.getElementById('div')
querySelector
let q = document.querySelector('div')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById
querySelector

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
getElementById	10793803.0 Ops/sec
querySelector	8595925.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one month ago):

LLMs can make mistakes. Check important info.

The benchmark you've provided is a test comparing two common JavaScript methods used for selecting elements in the DOM (Document Object Model): `getElementById` and `querySelector`. Below is an explanation of the tested methods, their pros and cons, and alternative approaches.

### Tested Options

1. **`getElementById`**:
   - **Description**: This method retrieves an element by its unique ID. Since IDs are supposed to be unique within a valid HTML document, this method is very efficient for locating elements.
   - **Pros**:
     - Speed: It is typically faster because the browser knows IDs should be unique and can immediately locate the target element without scanning the entire DOM.
     - Simplicity: The method only requires one argument (the ID string) and does not involve any complex selector syntax.
   - **Cons**:
     - Limitations: It can only be used to select elements by their ID, which may reduce flexibility compared to other methods that allow more complex selections.

2. **`querySelector`**:
   - **Description**: This method allows for more flexible selection using CSS selectors, enabling more complex queries beyond just element IDs.
   - **Pros**:
     - Flexibility: You can select elements using any valid CSS selector syntax, which allows for targeting classes, attributes, and other selectors.
     - Versatility: Ideal for selecting multiple elements or elements based on various criteria.
   - **Cons**:
     - Performance: It may be slower than `getElementById` because it has to parse the selector string and potentially scan through more DOM nodes to find matches.

### Benchmark Results

The results indicate how many executions per second each method could perform in the specified environment (Yandex Browser 24 on Windows). 
- `getElementById`: Approximately **3,419,804** executions/second.
- `querySelector`: Approximately **2,679,111** executions/second.

From these results, it is clear that `getElementById` performs significantly better than `querySelector` in this specific test case.

### Other Considerations

- **Use Case**: Choosing between these methods can depend on the use case. If you only need to retrieve an element by its ID, use `getElementById`. If you need to select elements using complex selectors (like classes or attribute selectors), `querySelector` is the way to go.
- **Browser Compatibility and Performance**: Although both methods are widely supported across modern browsers, performance can vary based on specific implementations and the structure of the DOM.
- **Selecting Multiple Elements**: If there’s a need to select multiple elements, consider using `querySelectorAll`, which returns all matches rather than just the first, but at a potentially lesser performance than `getElementById` for single element selection.

### Alternatives

- **`getElementsByClassName`** and **`getElementsByTagName`**: For selecting elements based on classes or tags, these methods provide options, although they return live HTMLCollections instead of static NodeLists.
- **`document.FQN`**: If you find yourself selecting many elements by ID in a known global context, you can store references to those elements for faster access.
- **Frameworks and Libraries**: Often, developers use libraries like jQuery for easier DOM manipulation, which internally utilizes these methods but adds abstraction and utility.

In summary, both `getElementById` and `querySelector` have their respective strengths, and the best choice depends on the specific requirements of your project. Running benchmarks like this helps identify the most efficient method for element selection within the constraints of your application's use case.

Related benchmarks:

test456 (version: 1)

Comparing performance of: getElementById vs querySelector

Created: one month ago by: Guest

Jump to the latest result

getElementById

querySelector

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one month ago):