All Avast software have ability to update themselves automatically. If you are connected to the Internet, virus database updates are downloaded and installed automatically without any user action. The availability of a new version is checked when an Internet connection is established, and every four hours afterwards.
Update files can also be downloaded from these pages if required e.g. if your computer does not have an Internet connection. Updates are usually released on a daily basis.
But, if you want to download the Avast Antivirus updates manually, then please follow the link below: