Benchmark: new Uint8Array() vs Uint8Array.from()

Script Preparation code:

var randomArray = Array.from({ length: 1000 }, () => Math.floor(Math.random() * 256))

Tests:

Test new Uint8Array()
new Uint8Array(randomArray)
Test Uint8Array.from()
Uint8Array.from(randomArray)

Historical Performance Data aggregated from 23 community runs

Desktop Results:

Chrome 23 runs

Test new Uint8Array()

1.2M/s

Test Uint8Array.from()

1.1M/s

View exact numbers

✓ Test new Uint8Array(): 1,150,502 ops/sec
• Test Uint8Array.from(): 1,081,445 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Test new Uint8Array()
Test Uint8Array.from()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36

Browser/OS: Chrome 148 on Mac OS X 10.15.7

View result in a separate tab

Test Uint8Array.from()

1.2M/s

Test new Uint8Array()

1.2M/s

View exact numbers

Test name	Executions per second
✓ Test Uint8Array.from()	1,218,778 Ops/sec
Test new Uint8Array()	1,213,124 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**What is being tested?**

The benchmark measures the performance difference between creating a `Uint8Array` using two different methods:

1. **`new Uint8Array()`**: This method creates a new `Uint8Array` object from an empty array.
2. **`Uint8Array.from()`**: This method creates a new `Uint8Array` object from an existing array.

**Options compared**

The benchmark compares the performance of these two methods on a randomly generated array of 1000 elements, where each element is a random integer between 0 and 255 (inclusive). The goal is to determine which method is faster for creating large arrays.

**Pros and Cons of each approach:**

* **`new Uint8Array()`**: This method creates an empty `Uint8Array` object and then populates it with the elements from the random array. This approach can be beneficial if you need to create a `Uint8Array` object without any pre-existing data, but it may incur additional overhead due to the repeated allocation of memory.
* **`Uint8Array.from()`**: This method creates a new `Uint8Array` object and populates it with the elements from the random array in a single operation. This approach is generally faster because it avoids the need for repeated allocation of memory.

**Library used**

In this benchmark, the `Uint8Array` class is not specifically tied to any library or framework. It is a built-in JavaScript class that is part of the ECMAScript standard.

**Special JS feature or syntax**

There are no specific special features or syntax mentioned in the benchmark. However, it's worth noting that the use of `new Uint8Array()` and `Uint8Array.from()` relies on JavaScript's array creation methods, which are supported by most modern browsers.

**Other alternatives**

If you need to create a large array quickly, there are other approaches you could consider:

* Using the `Array.prototype.fill()` method: This method can be used to populate an existing array with values, but it requires that the array is already populated.
* Using the `Array.prototype.set()` method: This method can be used to set the values of a large array in place, but it also requires that the array is already populated.
* Using native WebAssembly arrays (if supported by your browser): WebAssembly arrays provide a low-level interface for creating and manipulating arrays, which may offer better performance than JavaScript's built-in `Uint8Array` class.

Keep in mind that these alternatives may have different trade-offs and use cases compared to the original benchmark.

new Uint8Array() vs Uint8Array.from() (version: 0)

Test ArrayBuffer creation methods on a random Array

Comparing performance of: `Test new Uint8Array() vs Test Uint8Array.from()`

Created: 3 years ago by: Registered User

Go to the latest result

Test new Uint8Array()

Test Uint8Array.from()

Historical Performance Data aggregated from 23 community runs

Desktop Results:

Chrome 23 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

new Uint8Array() vs Uint8Array.from() (version: 0)

Test ArrayBuffer creation methods on a random Array

Comparing performance of: Test new Uint8Array() vs Test Uint8Array.from()

Created: 3 years ago by: Registered User

Go to the latest result

Test new Uint8Array()

Test Uint8Array.from()

Historical Performance Data aggregated from 23 community runs

Desktop Results:

Chrome 23 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Test new Uint8Array() vs Test Uint8Array.from()`