There is no such thing as a truly free antivirus. You're always going to “pay” with something. Most antivirus companies limit the free version of their software to only offer basic protection.
What virus protection is free?
Avast Free Antivirus detects and blocks all types of malware in real time to prevent them from infecting your computer. At the same time, it scans your PC to remove viruses and other malware automatically before they can do real damage.
Does free virus protection work?
For most of us, free antivirus is enough for home use and basic protection. It scans your device for common viruses, blocks dangerous files and apps, and removes anything malicious.