Benchmark: new Date().toISOString() vs new Date().toLocaleString()

Script Preparation code:

var timestamp = null;

Tests:

new Date().toISOString()
timestamp = new Date().toISOString();
new Date().toLocaleString()
timestamp = new Date().toLocaleString();

Historical Performance Data aggregated from 91 community runs

Desktop Results:

Chrome 82 runs

new Date().toISOString()

910K/s

new Date().toLocaleString()

503K/s

Fastest: new Date().toISOString() (1.8x faster)

View exact numbers

✓ new Date().toISOString(): 910,085 ops/sec
• new Date().toLocaleString(): 502,634 ops/sec

Firefox 9 runs

new Date().toISOString()

2.3M/s

new Date().toLocaleString()

399K/s

Fastest: new Date().toISOString() (5.9x faster)

View exact numbers

✓ new Date().toISOString(): 2,334,812 ops/sec
• new Date().toLocaleString(): 398,924 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().toISOString()
new Date().toLocaleString()

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36 Edg/148.0.0.0

Browser/OS: Chrome 148 on Windows

View result in a separate tab

new Date().toLocaleString()

543K/s

new Date().toISOString()

312K/s

View exact numbers

Test name	Executions per second
✓ new Date().toLocaleString()	543,276 Ops/sec
new Date().toISOString()	312,041 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 benchmark definition and test cases.

**What is tested?**

MeasureThat.net tests two approaches to generating strings from the JavaScript `Date` object: `toISOString()` and `toLocaleString()`. The goal is to compare their performance, specifically the execution speed of each method.

**Options compared:**

1. **`new Date().toISOString()`**: This method returns a string in ISO 8601 format (e.g., "2023-12-25T14:30:00.000Z").
2. **`new Date().toLocaleString()`**: This method returns a string representation of the date and time in a culturally-specific format (e.g., "December 25, 2023 2:30 PM").

**Pros and Cons of each approach:**

1. **`new Date().toISOString()`**:
	* Pros:
		+ Unambiguous, universally-recognized format.
		+ Can be easily parsed by computers and humans alike.
	* Cons:
		+ May not display the date in a culturally-sensitive way (e.g., month-long names instead of numbers).
2. **`new Date().toLocaleString()`**:
	* Pros:
		+ Displays dates in a culturally-specific format, making it more readable for human users.
	* Cons:
		+ Less widely recognized and parsed by computers compared to `toISOString()`.
		+ May not work as expected when dealing with certain date or time formats (e.g., UTC offsets).

**Library and purpose:**

The provided benchmark definition does not use any external libraries. However, it relies on the built-in JavaScript `Date` object.

**Special JS features or syntax:**

There are no special JS features or syntax mentioned in the provided benchmark definition.

**Other alternatives:**

If you need to generate a string representation of a date and time in JavaScript, other alternatives include:

1. **`Date.toISOString()`**: Returns a string in ISO 8601 format, similar to `toISOString()`.
2. **`Date.toUTCString()`**: Returns a string representation of the date and time in UTC (Coordinated Universal Time).
3. **`Intl.DateTimeFormat`.format()`**: Returns a string representation of the date and time in a culturally-specific format using the Intl.DateTimeFormat API.

These alternatives offer different trade-offs between readability, universality, and simplicity, depending on your specific use case.

new Date().toISOString() vs new Date().toLocaleString() (version: 0)

Comparing performance of: `new Date().toISOString() vs new Date().toLocaleString()`

Created: 5 years ago by: Guest

Go to the latest result

new Date().toISOString()

new Date().toLocaleString()

Historical Performance Data aggregated from 91 community runs

Desktop Results:

Chrome 82 runs

Firefox 9 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 Date().toISOString() vs new Date().toLocaleString() (version: 0)

Comparing performance of: new Date().toISOString() vs new Date().toLocaleString()

Created: 5 years ago by: Guest

Go to the latest result

new Date().toISOString()

new Date().toLocaleString()

Historical Performance Data aggregated from 91 community runs

Desktop Results:

Chrome 82 runs

Firefox 9 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().toISOString() vs new Date().toLocaleString()`