While is a paid subscription service, you can download and use it for free legally through an official trial period. Avast offers several ways to access its premium features without an immediate payment. How to Download Avast Premium Security for Free
Occasionally, Avast offers a 60-day trial, though this may require you to enter payment details that will be charged only after the trial ends unless canceled.
Run the installer as an administrator and follow the on-screen instructions to complete the setup.
You can download a 30-day free trial of the full software without providing any payment information.
To get started with your free trial, follow these steps from the official support guide : Visit the official Avast Premium Security page.