In tests conducted by Austrian lab AV-Comparatives on Windows 7, Avast Free Antivirus was slightly less effective.
Facing an array of malicious websites, it stopped 99.1 percent of malware in March 2017, 99.6 percent in April and 100 percent in May.
We wish Avast offered slightly quicker scans, but overall, it's our Editor's Choice. Starting at per year, Avast Internet Security adds a ransomware shield, a personal firewall and stronger protection against phishing attempts and malicious websites and a personal firewall.
Avast Free Antivirus starts with a traditional signature-based scanner that compares software against a database of known malware.
Its signature-matching scanner caught 99.8 percent of widespread known malware in May, and 99.9 percent in June.
Avast misidentified three harmless pieces of software — false positives — over both months, an acceptable rate.
You can manually start a full malware scan of the entire hard drive, or a Smart Scan that looks for malware in key locations and for software vulnerabilities, outdated browser add-ons, weak passwords and home network vulnerabilities.
Any file, folder or external drive can be scanned either through Avast's interface or with a right-click in Windows Explorer.
Avast Free Antivirus provides the two things you really want in a free AV program: a good level of security and a light system impact.
Wi-Fi Inspector can tell you what's wrong with your router's setup, including vulnerable settings.
It took about 5 minutes to find most of my connected devices and provided useful information about outdated firmware and weak passwords, but can't fix the faults – you'll have to do that yourself.
Avast Free Antivirus may not cost anything, but it bridges the gap between freemium and premium products with a password manager, a stand-alone hardened web browser and a network scanner, called Wi-Fi Inspector, that looks for vulnerabilities on other devices.
Most of the competition require a premium upgrade to get such features.