Benchmarking in Angular

Benchmarking is important — but how exactly do you do it?

Benchmarking is one of those things that we often hear about but rarely do ourselves. In part, it's mostly an afterthought until performance noticeably becomes annoying slow. Slow speeds are something that Angular is prone to, in part, because it's a framework and frameworks can be bulky.

But benchmarking is important - because it doesn't just tell us how good or bad our components are, it can also give insights into if there's a memory leak, any network latency issues, and how long it takes for an app to start up.

Without further ado, here's a comprehensive guide to benchmarking in Angular.

Component Rendering

When you visit a website or use an application, you expect it to respond quickly and smoothly. However, if the application is slow to respond or the interface is unresponsive, it can lead to frustration and a poor user experience. This is where benchmarking comes in.

Benchmarking is the process of measuring the performance of a system or application. In the context of Angular, benchmarking is important because it helps developers understand how their code performs in different situations. Specifically, measuring the time it takes for components to render on the page is important because it helps developers ensure that the application remains responsive and provides a smooth user experience.

By measuring the rendering time of components, we can identify performance bottlenecks in their code and optimize it for better performance. For example, if a component is taking a long time to render, developers can examine the code and find ways to make it more efficient. This can involve reducing the number of computations required, minimizing the number of network requests, or caching data to reduce the need for repetitive requests.

In Angular, you can measure component rendering time using Angular's built-in profiling tools. Here's a step-by-step guide to benchmarking component rendering in Angular:

Open the app.module.ts file in your Angular application.
Import the enableProdMode() function from @angular/core.

import { enableProdMode } from '@angular/core';

Call the enableProdMode() function to enable production mode in your application. This disables certain debugging features that can impact performance.

if (environment.production) {
  enableProdMode();
}

Use the ng.profiler.timeRendering() function to measure the time it takes for a component to render. This function takes no parameters and returns the time in milliseconds that it takes for the component to render.

ng.profiler.timeRendering();

To measure the rendering time of a specific component, add the ngAfterViewInit() lifecycle hook to the component class and call the ng.profiler.timeRendering() function in it. This ensures that the component has finished rendering before measuring the rendering time.

import { Component } from '@angular/core';

@Component({
  selector: 'app-my-component',
  template: '<div>My Component</div>'
})
export class MyComponent {
  ngAfterViewInit() {
    ng.profiler.timeRendering();
  }
}

Optimizing component rendering time is important because it ensures that the application remains fast and responsive, even when handling large amounts of data or complex user interactions. Additionally, a fast and responsive application can help improve user satisfaction and engagement, leading to better conversion rates and business outcomes.

The other way to benchmark your component

You can also run a benchmark test on Angular using the built-in ng-benchmark . This tool uses the Benchmark.js library to measure the performance of Angular components, services, and other parts of your application. The inherited perks of benchmark.js is that you to customize various aspects of the benchmarking process, such as the number of iterations, the sampling rate, and the output format. This makes it easy to fine-tune your benchmarks to suit your specific needs.

Here's an example of ng-benchmark in action: