Is Your Angular App Eating Up GBs of Memory? Here’s How to Fix It!

Angular applications can sometimes consume excessive memory, leading to performance issues, sluggish UI, and even crashes in extreme cases. Optimizing memory usage is crucial for delivering a smooth and efficient user experience. This article’ll explore common causes of high memory consumption in Angular applications and effective strategies to reduce it.

Common Causes of High Memory Usage in Angular

1. Memory Leaks: Components and services not properly cleaned up can cause memory leaks.
2. Excessive DOM Manipulation: Too many DOM elements or frequent updates can increase memory consumption.
3. Large Data Objects in Memory: Keeping large objects or arrays in memory unnecessarily bloats memory usage.
4. Unoptimized Change Detection: Running change detection frequently for all components degrades performance.
5. Improper Use of Observables: Subscriptions that are not unsubscribed can lead to memory leaks.
6. Large Bundle Size: Loading too much JavaScript can impact memory consumption.

Strategies to Reduce Memory Usage

1. Identify and Fix Memory Leaks

Memory leaks occur when allocated memory is not released after it is no longer needed. Use these techniques to identify and fix leaks:

• Use Chrome DevTools Memory Profiler: Open DevTools (F12), go to the Memory tab, and take snapshots to analyze memory growth.
• Manually Unsubscribe from Observables:

import { Subscription } from 'rxjs';

export class ExampleComponent implements OnDestroy {
  private subscription: Subscription;

  ngOnInit() {
    this.subscription = this.someService.getData().subscribe(data => {
      console.log(data);
    });
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

• Use the async pipe instead of subscribing manually:

<div *ngIf="data$ | async as data">{{ data }}</div>

2. Optimize Change Detection