Benchmark: Intl.NumberFormat vs toLocalString vs cached Intl.NumberFormat

Script Preparation code:

var formatter = new Intl.NumberFormat("en-US");

Tests:

Intl.NumberFormat
var a = new Intl.NumberFormat("en-US").format("10000");
toLocalString
var a = "10000".toLocaleString("en-US");
Intl.NumberFormat With cached formatter
var a = formatter.format("10000");

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

toLocalString

12.3M/s

Intl.NumberFormat With cached formatter

1.5M/s

Intl.NumberFormat

32K/s

Fastest: toLocalString (381.7x faster)

View exact numbers

✓ toLocalString: 12,293,094 ops/sec
• Intl.NumberFormat With cached formatter: 1,500,707 ops/sec
• Intl.NumberFormat: 32,204 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
Intl.NumberFormat
toLocalString
Intl.NumberFormat With cached formatter

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 YaBrowser/25.2.0.0 Safari/537.36

Browser/OS: Yandex Browser 25 on Mac OS X 10.15.7

View result in a separate tab

toLocalString

34.6M/s

Intl.NumberFormat With cached formatter

4.2M/s

Intl.NumberFormat

85K/s

View exact numbers

Test name	Executions per second
✓ toLocalString	34,586,104 Ops/sec
Intl.NumberFormat With cached formatter	4,185,154 Ops/sec
Intl.NumberFormat	85,245 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 provided JSON and explain what is being tested.

**Benchmark Overview**

The benchmark compares three approaches for formatting numbers in JavaScript:

1. `Intl.NumberFormat`
2. `toLocaleString` method
3. Using a cached instance of `Intl.NumberFormat`

**Options Compared**

* `Intl.NumberFormat`: formats numbers using the Internationalization API, which provides support for locale-specific formatting.
* `toLocaleString` method: formats numbers based on the browser's built-in locale settings.
* Cached `Intl.NumberFormat`: uses a pre-cached instance of `Intl.NumberFormat` to avoid re-creating the formatter on each execution.

**Pros and Cons**

* `Intl.NumberFormat`:
	+ Pros: provides fine-grained control over formatting options, supports multiple locales, and can be more efficient than other methods for complex formatting.
	+ Cons: requires internationalization support in the browser, and may not work as expected in older browsers or those with limited locale data.
* `toLocaleString` method:
	+ Pros: easy to use and works well out of the box, but may not provide fine-grained control over formatting options.
	+ Cons: depends on the browser's built-in locale settings, which can vary between users and devices.
* Cached `Intl.NumberFormat`:
	+ Pros: avoids re-creating the formatter on each execution, making it faster than using a new instance for each test case.
	+ Cons: may not work if the cached instance is garbage collected or modified during the benchmark run.

**Library/Technology Used**

The `Intl.NumberFormat` API uses the ECMAScript Internationalization API (ECMA-402) to provide support for locale-specific formatting. The `toLocaleString` method relies on the browser's built-in locale settings, which are implemented using the same API.

**Special JavaScript Feature/Syntax**

None mentioned in this specific benchmark. However, it's worth noting that some browsers may have additional features or syntax for internationalization and localization that can be used with `Intl.NumberFormat`.

**Alternatives**

Other approaches for formatting numbers in JavaScript include:

* Using a library like Moment.js or Luxon, which provide more extensive formatting options.
* Implementing custom formatting logic using plain JavaScript.
* Using a template engine like Handlebars or Mustache to render formatted templates.

Keep in mind that the choice of approach depends on the specific requirements and constraints of your project.

Intl.NumberFormat vs toLocalString vs cached Intl.NumberFormat (version: 0)

Comparing performance of: `Intl.NumberFormat vs toLocalString vs Intl.NumberFormat With cached formatter`

Created: 3 years ago by: Guest

Go to the latest result

Intl.NumberFormat

toLocalString

Intl.NumberFormat With cached formatter

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Intl.NumberFormat vs toLocalString vs cached Intl.NumberFormat (version: 0)

Comparing performance of: Intl.NumberFormat vs toLocalString vs Intl.NumberFormat With cached formatter

Created: 3 years ago by: Guest

Go to the latest result

Intl.NumberFormat

toLocalString

Intl.NumberFormat With cached formatter

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 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: `Intl.NumberFormat vs toLocalString vs Intl.NumberFormat With cached formatter`