Benchmark: Date.now() vs new Date().getTime() vs performance.now() vs +new Date()

Script Preparation code:

var timestamp = null;

Tests:

Date.now()
timestamp = Date.now();
new Date().getTime();
timestamp = new Date().getTime();
performance.now()
timestamp = performance.now()
new date
timestamp = +new Date();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date.now()
new Date().getTime();
performance.now()
new date

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36

Browser/OS: Chrome 88 on Windows

View result in a separate tab

Test name	Executions per second
Date.now()	1530192.9 Ops/sec
new Date().getTime();	1354100.1 Ops/sec
performance.now()	1180149.4 Ops/sec
new date	1158037.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON.

**Benchmark Definition**

The benchmark definition is comparing the performance of four different methods to get the current time:

1. `Date.now()`
2. `new Date().getTime()`
3. `performance.now()`
4. `+new Date()` (note: this uses the unary plus operator, which converts the result to a number)

**Options Compared**

The options being compared are all ways to get the current time in JavaScript. Here's a brief explanation of each:

* `Date.now()`: This method returns the timestamp as an integer value in milliseconds since the Unix epoch (January 1, 1970, 00:00:00 UTC). It's fast and simple but may not be suitable for all use cases.
* `new Date().getTime()`: This method creates a new `Date` object and gets its time in milliseconds since the Unix epoch. While it provides more context than `Date.now()`, it's slower due to the creation of a new object.
* `performance.now()`: This method returns the timestamp as an integer value in milliseconds since the performance start (a high-resolution timer). It's designed for measuring performance and is generally faster than `Date.now()` or `new Date().getTime()`.
* `+new Date()`: This method creates a new `Date` object, gets its time, and then converts it to a number using the unary plus operator. The result is similar to `Date.now()`, but with an additional layer of abstraction.

**Pros and Cons**

Here are some pros and cons for each option:

* `Date.now()`:
	+ Pros: Fast, simple, and widely supported.
	+ Cons: May not provide enough context or precision for some use cases.
* `new Date().getTime()`: 
	+ Pros: Provides more context than `Date.now()`, can be used with dates.
	+ Cons: Slower due to the creation of a new object.
* `performance.now()`: 
	+ Pros: Designed for performance, high-resolution timer.
	+ Cons: May not be supported in older browsers or environments.
* `+new Date()`:
	+ Pros: Similar to `Date.now()` but with an additional layer of abstraction.
	+ Cons: Slower and more complex due to the creation of a new object.

**Library**

None of these options use a library specifically. They are all built-in methods or operators in JavaScript.

**Special JS Features/Syntax**

There's no special JavaScript feature or syntax used in this benchmark. It only relies on standard JavaScript features like `Date` objects and arithmetic operators.

**Other Alternatives**

If you need more precision or context than what these options provide, you might consider using other methods:

* `Date.now()`: If you need a high-resolution timer but want to avoid the performance overhead of `performance.now()`.
* `new Date()`: If you need to work with dates and times in a more explicit way.
* Other libraries or frameworks: Depending on your specific use case, you might find it useful to use a library like moment.js or luxon for date and time manipulation.

Overall, the choice of which option to use depends on your specific performance requirements, the level of precision needed, and the compatibility constraints of your project.

Related benchmarks:

Date.now() vs new Date().getTime() vs performance.now() vs +new Date() (version: 0)

Comparing performance of: Date.now() vs new Date().getTime(); vs performance.now() vs new date

Created: 3 years ago by: Guest

Jump to the latest result

Date.now()

new Date().getTime();

performance.now()

new date

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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