Benchmark: new Intl.DateTimeFormat vs new Date().toLocaleDateString()

Script Preparation code:

var options = {
  year: 'numeric', month: 'numeric', day: 'numeric',
  hour: 'numeric', minute: 'numeric', second: 'numeric',
  hour12: false,
  fractionalSecondDigits: 3,
}

Tests:

new Date()
(new Date()).toISOString().trim().replace('T', ' ').replace('Z', '')
Intl.DateTimeFormat()
new Intl.DateTimeFormat('en-US', options).format(new Date())
Date().toLocaleString()
new Date().toLocaleString("en-US", options)
JavaScript Date Time format
let date_time = new Date() let formatted_date = date_time.getFullYear() + "-" + (date_time.getMonth() + 1) + "-" + date_time.getDate() + " " + date_time.getHours() + ":" + date_time.getMinutes() + ":" + date_time.getSeconds() + "." + date_time.getMilliseconds()
JavaScript Date Time format using Template Strings.
let date_time = new Date() let formatted_date = `${date_time.getFullYear()}-${date_time.getMonth() + 1}-${date_time.getDate()} ${date_time.getHours()}:${date_time.getMinutes()}:${date_time.getSeconds()}.${date_time.getMilliseconds()}`

Historical Performance Data aggregated from 32 community runs

Desktop Results:

Chrome 27 runs

JavaScript Date Time format using Template Strings.

3.3M/s

JavaScript Date Time format

3.3M/s

new Date()

1.2M/s

Date().toLocaleString()

22K/s

Intl.DateTimeFormat()

20K/s

Fastest: JavaScript Date Time format using Template Strings. (164.9x faster)

View exact numbers

✓ JavaScript Date Time format using Template Strings.: 3,344,126 ops/sec
• JavaScript Date Time format: 3,339,924 ops/sec
• new Date(): 1,160,514 ops/sec
• Date().toLocaleString(): 22,165 ops/sec
• Intl.DateTimeFormat(): 20,279 ops/sec

Firefox 5 runs

JavaScript Date Time format using Template Strings.

4.4M/s

JavaScript Date Time format

3.1M/s

new Date()

2.8M/s

Intl.DateTimeFormat()

16K/s

Date().toLocaleString()

15K/s

Fastest: JavaScript Date Time format using Template Strings. (291.0x faster)

View exact numbers

✓ JavaScript Date Time format using Template Strings.: 4,375,964 ops/sec
• JavaScript Date Time format: 3,082,723 ops/sec
• new Date(): 2,786,477 ops/sec
• Intl.DateTimeFormat(): 16,299 ops/sec
• Date().toLocaleString(): 15,039 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
new Date()
Intl.DateTimeFormat()
Date().toLocaleString()
JavaScript Date Time format
JavaScript Date Time format using Template Strings.

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser/OS: Chrome 141 on Windows

View result in a separate tab

JavaScript Date Time format using Template Strings.

6.4M/s

JavaScript Date Time format

6.3M/s

new Date()

638K/s

Date().toLocaleString()

17K/s

Intl.DateTimeFormat()

15K/s

View exact numbers

Test name	Executions per second
✓ JavaScript Date Time format using Template Strings.	6,414,160 Ops/sec
JavaScript Date Time format	6,306,896 Ops/sec
new Date()	638,444 Ops/sec
Date().toLocaleString()	16,723 Ops/sec
Intl.DateTimeFormat()	14,913 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a benchmark test case named "new Intl.DateTimeFormat vs new Date().toLocaleDateString()". This test compares the performance of two approaches to format dates in JavaScript:

1. Using `Intl.DateTimeFormat` with specific options
2. Using `Date()` and `toLocaleString()` methods

**Options Comparison**

The test uses specific options for `Intl.DateTimeFormat`, which are compared to the default formatting behavior of `Date().toLocaleString()`. The options used are:

* `year`: formats the year as a number (numeric)
* `month`: formats the month as a number (numeric)
* `day`: formats the day as a number (numeric)
* `hour`: formats the hour as a number (numeric)
* `minute`: formats the minute as a number (numeric)
* `second`: formats the second as a number (numeric)
* `hour12`: sets the hour format to 24-hour clock (false, default)
* `fractionalSecondDigits`: formats the fractional seconds part to 3 digits

**Pros and Cons**

* Using `Intl.DateTimeFormat` provides more control over formatting options and can handle different locales.
	+ Pros:
		- More flexible and customizable
		- Can handle dates in different locales
	+ Cons:
		- May be slower due to the additional complexity of the function
* Using `Date()` and `toLocaleString()` is simpler and more straightforward.
	+ Pros:
		- Faster and more lightweight
		- Easier to understand and implement
	+ Cons:
		- Less flexible and customizable
		- May not work correctly for all locales

**Library: Intl.DateTimeFormat**

`Intl.DateTimeFormat` is a part of the ECMAScript Internationalization API, which provides functions for formatting dates and numbers according to the rules of different languages. The `DateTimeFormat` function takes an options object with various properties that control the formatting behavior.

**Special JS Feature/Syntax: Template Literals (Template Strings)**

The test also includes two versions of the JavaScript Date Time format using template literals:

1. Old syntax:
```javascript
let date_time = new Date()
let formatted_date = date_time.getFullYear() + "-" + (date_time.getMonth() + 1) + "-" + date_time.getDate() + " " + date_time.getHours() + ":" + date_time.getMinutes() + ":" + date_time.getSeconds() + "." + date_time.getMilliseconds()
```

2. New syntax:
```javascript
let date_time = new Date()
let formatted_date = `${date_time.getFullYear()}-${date_time.getMonth() + 1}-${date_time.getDate()} ${date_time.getHours()}:${date_time.getMinutes()}:${date_time.getSeconds()}.${date_time.getMilliseconds()}\r\n`
```

The main difference between the two is that the old syntax uses string concatenation (`+`), while the new syntax uses template literals (`${}`). Template literals provide a more readable and concise way to format strings, but they are also slightly slower due to the additional complexity of the function.

**Other Alternatives**

If you need to compare performance with other date formatting approaches, consider adding tests for:

* Using `Date()` without any formatting options
* Using `Moment.js` or other third-party libraries for date formatting
* Using CSS or HTML for date formatting (e.g., using `:before` pseudo-elements)

Keep in mind that each alternative may have its own trade-offs and considerations, so make sure to test and analyze the performance of each approach accordingly.

new Intl.DateTimeFormat vs new Date().toLocaleDateString() (version: 0)

Comparing performance of: `new Date() vs Intl.DateTimeFormat() vs Date().toLocaleString() vs JavaScript Date Time format vs JavaScript Date Time format using Template Strings.`

Created: 5 years ago by: Guest

Go to the latest result

new Date()

Intl.DateTimeFormat()

Date().toLocaleString()

JavaScript Date Time format

JavaScript Date Time format using Template Strings.

Historical Performance Data aggregated from 32 community runs

Desktop Results:

Chrome 27 runs

Firefox 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):

new Intl.DateTimeFormat vs new Date().toLocaleDateString() (version: 0)

Comparing performance of: new Date() vs Intl.DateTimeFormat() vs Date().toLocaleString() vs JavaScript Date Time format vs JavaScript Date Time format using Template Strings.

Created: 5 years ago by: Guest

Go to the latest result

new Date()

Intl.DateTimeFormat()

Date().toLocaleString()

JavaScript Date Time format

JavaScript Date Time format using Template Strings.

Historical Performance Data aggregated from 32 community runs

Desktop Results:

Chrome 27 runs

Firefox 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: `new Date() vs Intl.DateTimeFormat() vs Date().toLocaleString() vs JavaScript Date Time format vs JavaScript Date Time format using Template Strings.`