Benchmark: test789 - MeasureThat.net

HTML Preparation code:

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

Tests:

querySelectorAll
document.querySelectorAll('#form').forEach(function (e) { console.log(e.target) })
querySelector
let qwe = document.querySelector('#form') console.log(qwe)
getElementById
let qwe = document.getElementById('form') console.log(qwe)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
querySelectorAll
querySelector
getElementById

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/128.0.0.0 YaBrowser/24.10.0.0 Safari/537.36

Browser/OS: Yandex Browser 24 on Windows

View result in a separate tab

Test name	Executions per second
querySelectorAll	97357.6 Ops/sec
querySelector	99581.6 Ops/sec
getElementById	105777.5 Ops/sec

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

LLMs can make mistakes. Check important info.

The benchmark provided tests three different methods for selecting HTML elements in the DOM (Document Object Model) using JavaScript. Specifically, it evaluates the performance of the following methods:

1. **`getElementById`**: This method is used to retrieve an element based on its unique identifier (id). In the benchmark, it retrieves the element with the id of "form".

2. **`querySelector`**: This method allows you to select the first element that matches a specified CSS selector. In this case, it retrieves the same element using the CSS id selector syntax `'#form'`.

3. **`querySelectorAll`**: Unlike `querySelector`, which returns only the first matching element, `querySelectorAll` returns a NodeList of all elements matching the specified selector. Here, it attempts to retrieve all elements with the id "form", which should return only one element but requires iterations over the resulting NodeList in the benchmark.

### Performance Comparison

The benchmark results indicate how many times each method can execute per second:

- **getElementById**: About 105,777 executions per second
- **querySelector**: About 99,581 executions per second
- **querySelectorAll**: About 97,358 executions per second

### Pros and Cons of Each Method

1. **`getElementById`**
   - **Pros**:
     - Fastest method for selecting an element since it directly accesses elements by their unique ID.
     - Guaranteed to return a single element or `null` if not found, which simplifies logic.
   - **Cons**:
     - Can only select by id, limiting flexibility in element selection.

2. **`querySelector`**
   - **Pros**:
     - Offers more flexibility than `getElementById`, as it can use any valid CSS selector (class names, tag names, attributes, etc.).
     - Returns the first matching element, which can be more efficient in cases where you only need one element.
   - **Cons**:
     - Slightly slower than `getElementById` due to its broader selection syntax.

3. **`querySelectorAll`**
   - **Pros**:
     - Allows selection of multiple elements at once with a CSS selector, useful for scenarios needing to work with batches of elements.
   - **Cons**:
     - The overhead of iterating over the resulting NodeList (even if it's a single element) makes it the slowest in this scenario.
     - Returns a NodeList, which may require additional handling in certain contexts.

### Other Considerations

- The choice between these methods often comes down to what you need for your specific use case: if you need to access one element, `getElementById` is best; `querySelector` offers more versatility; and `querySelectorAll` is suitable when needing to batch access multiple elements.

### Alternatives

Additionally, there are other ways to select elements in the DOM that were not tested in this benchmark:

- **`getElementsByClassName`**: Selects all elements with a specified class name. It returns a live HTMLCollection, which can be a performance hit if the collection has to be updated frequently.
  
- **`getElementsByTagName`**: Selects elements by their tag name and also returns a live HTMLCollection.

- **jQuery**: While not directly compared in this benchmark, many developers use jQuery's selector methods (like `$('.class')`) which can be convenient but may introduce performance overhead due to jQuery's abstractions over native methods.

In conclusion, the benchmark effectively compares how efficiently different DOM element selection methods operate under consistent conditions, providing valuable insights for developers optimizing for performance in web applications.

Related benchmarks:

test789 (version: 1)

Comparing performance of: querySelectorAll vs querySelector vs getElementById

Created: one year ago by: Guest

Jump to the latest result

querySelectorAll

querySelector

getElementById

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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