Benchmark: Time Taken - MeasureThat.net

Tests:

Date.now()
const start = Date.now(); const total = Date.now() - start;
performance.now()
const start = performance.now(); const total = performance.now() - start;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date.now()
performance.now()

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/125.0.0.0 Safari/537.36

Browser/OS: Chrome 125 on Windows

View result in a separate tab

Test name	Executions per second
Date.now()	5590011.5 Ops/sec
performance.now()	3325166.8 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmarking process involves measuring the execution time of a specific piece of code or function, and the results are displayed in a user-friendly format.

**Benchmark Definition**

The provided JSON represents a benchmark definition with two test cases:

1. **Date.now()**
2. **performance.now()**

The "Name" field specifies that the benchmark is measuring the time taken for each test case.

**Options Compared**

Two options are being compared:

*   **Date.now()**: This function returns the number of milliseconds since the Unix epoch (January 1, 1970) in the current timezone. It's a simple way to get the current time.
*   **performance.now()**: This function returns the value (in fraction of a second) of a performance counter that represents the amount of time elapsed since an arbitrary start point.

**Pros and Cons**

Here are some pros and cons for each option:

### Date.now()

Pros:

*   Simple to use
*   Only requires a single line of code

Cons:

*   May not be suitable for high-performance applications due to the following reasons:
    *   **Accuracy**: The `Date` object's internal timestamp might not be updated at the exact moment when you call `Date.now()`. This can lead to inaccurate results, especially in cases where system time is adjusted manually.
    *   **Precision**: The function returns values with millisecond precision, which may not always be necessary. Higher precision could result in slightly increased overhead due to more frequent updates of the internal timestamp.
*   **Browser Support**: It has excellent browser support.

### performance.now()

Pros:

*   More accurate than `Date.now()` since it takes into account more factors like system clock adjustments, CPU scheduling, and other non-deterministic events that can impact accuracy in general. It provides higher precision compared to Date.now(), as it returns values with microsecond precision (but not nanosecond).

Cons:

*   Requires a second line of code
*   Can be slower due to the increased complexity of modern CPUs

**Library and Purpose**

There is no explicit library mentioned in the benchmark definition.

However, the use of `performance.now()` suggests that the developer is aware of and using the performance APIs provided by the browser. The performance APIs are a set of low-level functions for measuring various aspects of JavaScript execution time and other performance metrics.

**Special JS Feature or Syntax**

Neither of the test cases utilizes any special JavaScript features or syntax. They only utilize built-in functions (`Date.now()` and `performance.now()`).

If you were to create a benchmark that utilized some advanced features like async/await, Web Workers, or even micro-optimization techniques (like bit shifting), those would be worth exploring.

**Other Alternatives**

If you wanted to explore alternatives to the options mentioned above, here are a few:

*   **Intl.DateTimeFormat**: This API can be used for comparing dates between different languages and locales. However, it might not provide any inherent performance advantage over `Date.now()` when measuring basic timing differences.

Please note that these alternatives will have varying degrees of applicability based on the specific requirements of your benchmarking task.

Keep in mind that creating a good JavaScript benchmark should take into account several factors, including the system configuration, browser, and other non-deterministic variables.

Related benchmarks:

Time Taken (version: 0)

Comparing performance of: Date.now() vs performance.now()

Created: one year ago by: Guest

Jump to the latest result

Date.now()

performance.now()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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