Toggle navigation
MeasureThat.net
Create a benchmark
Tools
Feedback
FAQ
Register
Log In
document.querySelectorAll vs document.body.querySelectorAll
(version: 0)
Comparing performance of:
document.querySelectorAll vs document.body.querySelectorAll
Created:
7 years ago
by:
Guest
Jump to the latest result
HTML Preparation code:
<div class="test"></div>
Tests:
document.querySelectorAll
document.querySelectorAll(".test")
document.body.querySelectorAll
document.body.querySelectorAll(".test")
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
Fork
Test case name
Result
document.querySelectorAll
document.body.querySelectorAll
Fastest:
N/A
Slowest:
N/A
Latest run results:
No previous run results
This benchmark does not have any results yet. Be the first one
to run it!
Autogenerated LLM Summary
(model
gemma2:9b
, generated one year ago):
This benchmark compares two ways to select HTML elements: **`document.querySelectorAll(".test")`:** This approach directly uses the `querySelectorAll` method on the entire document object (`document`). It searches for all elements with the class "test" within the entire HTML structure. **`document.body.querySelectorAll(".test")`:** This approach first accesses the `<body>` element of the HTML document and then uses `querySelectorAll` on that specific body element. It will only search for elements with the class "test" *within* the `<body>` section. **Pros and Cons:** * **`document.querySelectorAll(".test")`**: * **Pro:** Potentially faster if the elements are spread throughout the entire document, as it avoids an extra level of navigation to access the `<body>`. * **Con:** Might be slightly slower if the target elements are exclusively within the `<body>` since it scans a larger portion of the DOM tree. * **`document.body.querySelectorAll(".test")`**: * **Pro:** More specific and focused, as it limits the search to the `<body>`. This can potentially improve performance if the target elements are only within the body. * **Con:** Might be slightly slower than `document.querySelectorAll` if the target elements exist outside the `<body>` section. **Other Considerations:** * **DOM Structure:** The actual performance difference between these approaches heavily depends on the size and structure of your HTML document. If you know that all relevant elements are within the `<body>`, using `document.body.querySelectorAll` is likely more efficient. * **Caching:** Browsers often cache the results of `querySelectorAll` for performance optimization. Subsequent calls with the same selector might benefit from this caching. **Alternatives:** * **`getElementById`:** Use when you know the exact ID of the element you're looking for. This is generally faster than using `querySelectorAll`. * **CSS Selectors:** You can use more complex CSS selectors within both methods for finer-grained element selection, potentially impacting performance depending on the selector complexity. Remember that these are general guidelines. Benchmarking your specific scenario with real-world data will give you the most accurate performance insights.
Related benchmarks:
document.querySelectorAll vs document.body.querySelectorAll
getElementsByClassName()[0] vs querySelectorAll
document.body vs document.querySelector
JS getElementsByClassName vs querySelectorAll
Comments
Confirm delete:
Do you really want to delete benchmark?