Benchmark: TextDecoder('utf-16') vs String.fromCharCode

Script Preparation code:

var bytes = [84, 104, 105, 115, 32, 105, 115, 32, 97, 32, 115, 97, 109, 112, 108, 101, 32, 112, 97, 114, 97, 103, 114, 97, 112, 104, 46];
var bufferArray = new Uint16Array(bytes);
var decoder = new TextDecoder('utf-16');

Tests:

String.fromCharCode
String.fromCharCode.apply(null, bufferArray);
TextDecoder
decoder.decode(bufferArray);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String.fromCharCode
TextDecoder

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/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Windows

View result in a separate tab

Test name	Executions per second
String.fromCharCode	3102089.0 Ops/sec
TextDecoder	2119223.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing two approaches: using `TextDecoder` to decode UTF-16 encoded byte arrays, and using `String.fromCharCode` with an array of Unicode code points to create a string from the same byte array.

**What are we testing?**

We're testing which approach is faster. In this case, it's about decoding a specific set of bytes that represent a text snippet in UTF-16 encoding.

**Options being compared:**

1. **TextDecoder**: A built-in JavaScript API for decoding text from binary data.
2. **String.fromCharCode**: A method that creates a string by specifying an array of Unicode code points.

**Pros and Cons:**

* **TextDecoder**:
	+ Pros: More efficient for large amounts of encoded data, handles encoding errors more robustly, and provides better performance.
	+ Cons: May have overhead due to its complex internal workings and potential issues with older browsers or versions of JavaScript.
* **String.fromCharCode**:
	+ Pros: Lightweight, easy to use, and widely supported across browsers and versions of JavaScript. However, it may be slower for large inputs and can produce errors if not used carefully.
	+ Cons: Can be brittle, prone to issues with encoding, and less efficient than TextDecoder.

**Library/Library usage:**

The benchmark uses the `TextDecoder` API, which is a built-in part of JavaScript's DOM (Document Object Model). This library provides an interface for decoding text from binary data. It's optimized for performance and handles various encoding schemes, including UTF-16.

**Special JS feature or syntax:**

There are no special features or syntax used in this benchmark. Both `TextDecoder` and `String.fromCharCode` are standard JavaScript APIs that don't rely on any specific language features.

**Other alternatives:**

If you want to measure the performance of other approaches, you could consider:

* Using a library like ICU (International Components for Unicode) or a similar Unicode processing library.
* Implementing your own decoding logic using bitwise operations and string manipulation.
* Comparing the performance of different browser-specific APIs, such as WebKit's `NSStringFromCF` or Mozilla's `nsStringFromBytes`.

Keep in mind that these alternatives might have their own trade-offs and may not be directly comparable to the benchmarked approaches.

Related benchmarks:

TextDecoder('utf-16') vs String.fromCharCode (version: 0)

Comparing performance of: String.fromCharCode vs TextDecoder

Created: 2 years ago by: Guest

Jump to the latest result

String.fromCharCode

TextDecoder

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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