Avast Antivirus is a family of Internet security applications developed by Avast Software  for Microsoft Windows , MacOS , Android and iOS . The Avast Antivirus products include free and proprietary versions That Provide computer security , browser security , antivirus software , firewall , anti-phishing , anti-spyware and anti-spam Among other services. 
As of 2017, Avast is the most popular antivirus on the market,  and has the largest share of the market for antivirus applications. 
Avast programs are only available to internet-connected devices, and are available in 45 languages. The Avast product range includes the following: 
Microsoft Windows products
- Avast Free Antivirus – Free for non-commercial and home use. This product’s features include antivirus with antispyware, Avast Passwords, Secure HTTPS scanning, streaming updates, hardened mode, DeepScreen, Home Network Security scanner, Do Not Track, SiteCorrect, antiphishing, anti-malware, Smart Scan, Rescue Disk, and Software Updater ( manual), Ransomware Protection. Requires 1-year registration and includes advertisements for other Avast products.
- Avast Pro Antivirus – For home use. Includes all features of the Free version, with the addition of SafeZone Browser, Secure DNS, and Sandbox. Does not require registration, but does require a license or activation code.
- Avast Internet Security – Includes the features of Pro, with the addition of a silent firewall and antispam. Does not need registration, but does require a license or activation code.
- Avast Premier – Includes all the features of Internet Security, with the addition of a data shredder, an “AccessAnywhere” service, and an automatic software updater (for programs such as Google Chrome ). Does not require registration, but does require a license or activation code.
- Avast Free Mac Security – An antivirus solution for Apple Macintosh running machines macOS based on a central virus-scanning daemon; offers three shields, on-demand scanning and WebRep clients which are automatically installed to uc browser, Safari, Chrome and Firefox browsers.
- Avast for Business – SMBs. It is a cross-platform solution that includes antivirus protection, Web threat scanning and integrated browser protection, and a cloud management console. 
- Endpoint Protection / Protection Plus / Protection Suite / Protection Suite Plus
- Email Server Security
- File Server Security
- Security Suite for Linux
Mobile products for Android
Antivirus and Anti-Theft (share of Avast Mobile Premium)
- Avast Mobile Security & Antivirus – Free app for Android devices. Includes a virus scanner, virus removal, protector, network meter, app manager, app lock, backup, and a firewall on rooted phones.
- Avast Mobile Premium – Premium app for Android devices. Includes app locking, geo-fencing, SMS remote, data recovery, Anti Theft and identification, and extended backup.
- Avast SecureLine
- Comparison of antivirus software
- ^ Jump up to:a b Avast worth ‘upwards of $ 2 trillion’; no IPO before 2017 Reuters . Published on October 29, 2015
- Jump up^ “AVAST Software sro: Private Company Information – Bloomberg” . Retrieved 24 February 2017 .
- Jump up^ OPSWAT. “Antivirus and Compromised Device Report: May 2017” .
- Jump up^ “Avast antivirus Downloads” .
- Jump up^ Kovacs, Eduard. “Avast Launches Free Security Solution for Businesses”, Security Week 24 February 2015. Retrieved on 23 March 2015.