Windows PC users need a strong antivirus program to ward off malware attacks, to keep their computers running efficiently and to safeguard their online identities and personal information. The best paid antivirus suites have many features to protect children online, manage security on mobile devices, and monitor a computer's firewall, software updates and other features. But some users just don't want, or can't afford, to pay a yearly subscription fee for those extra features, and may need to go with a free antivirus program.
If that describes you, you've come to the right place. We've evaluated the best free antivirus programs based on their malware protection, system impact, ease of use and useful extra features. If you're undecided, check out our free vs paid antivirus comparison first.
So which free PC antivirus product would be best for you? Of the seven free antivirus programs we've recently reviewed, Kaspersky Free Antivirus barely edged out Bitdefender Antivirus Free Edition for the top spot. Both offer excellent protection against malware without slowing down your system, but Kaspersky lets you schedule scans and has a quick-scan option.
Bitdefender, however, is still the best "set it and forget it" free antivirus option. After installation, it takes care of itself and doesn’t need user intervention. If you need to install antivirus software on your grandparents' computer but don't have time to monitor it, this might be the perfect solution.
Both Kaspersky's and Bitdefender's products offer only the basics. If you want features such as a password manager or a hardened web browser, normally found in midpriced paid antivirus suites, then Avast Free Antivirus might be for you. But its malware protection isn't as good as the top two and its performance impact is heavier.
Latest Security Alerts and Threats
— Researchers found yet more security flaws in Intel CPUs related to the Spectre and Meltdown flaws. ADVICE: Update your Intel-based Windows, macOS and Chrome OS devices to mitigate the flaws, though you might see some slowdowns as a result.
— Microsoft took the unusual step of patching Windows XP and Windows Server 2003, both five years past their end-of-life dates, after a wormable vulnerability was discovered. Windows 7 got the patch as well. ADVICE: Update your Windows 7 systems, and your XP ones too, if you've still got any.
— Nearly three dozen models of Linksys Wi-Fi routers may be leaking sensitive information about the computer, smartphones, printers and other devices on users' home networks. It's not clear if Linksys' firmware patch works. ADVICE: If nothing else, make sure the administrative username and password on your Linksys router are not the factory defaults. Then wait for a new firmware patch.
How We Tested
To evaluate installation, ease of use, interface and performance impact, we installed each AV program on the same Asus X555LA laptop, which ran Windows 10 and featured an Intel Core i3-4005U processor, 6GB of RAM and 36GB of data on a 500GB hard drive.
We conducted our own tests on how much each antivirus product affected our laptop's performance, using our custom OpenOffice benchmark. We timed how long it took to run a quick scan and a full scan while the laptop crunched numbers in the background.
We also assessed how easy each program was to use, the number of useful extra features it offered (including free add-on software) and how insistently each program nagged us to upgrade to paid software.
Our malware-detection data comes from four evaluation labs: AV-TEST in Germany, AV-Comparatives in Austria, SE Labs in England and our own lab in Utah. Each lab regularly tests major antivirus products for their abilities to detect zero-day malware and other threats.
1. Kaspersky Free Antivirus
Lean and mean.Pros: Excellent malware protection; moderate performance hit; fast scans
Cons: Bare-bones with few extra features
Kaspersky Lab doesn't advertise that it has a free antivirus product, and doesn't make it easy to find the download page. Too bad, because this is one of the best free antivirus products we've ever tested, with a no-nonsense but comprehensible interface, a light-to-moderate system-performance impact and Kaspersky's unbeatable malware protection. The only reason we're not giving Kaspersky Free Antivirus a 4.5/5 rating is because it offers no extra features.
2. Bitdefender Antivirus Free Edition
No muss, no fuss.Pros: Top protection against malware; super-easy to use; small performance impact
Cons: No customization options; no quick scans or scan scheduling
Like Kaspersky, Bitdefender Antivirus Free Edition offers nothing but the basics, and its malware protection is just as good, if a bit more prone to false-positive malware detections. Its scans are lighter on the system than Kaspersky's, but it offers fewer options — you can't even schedule a scan. It's best for users who want a set-it-and-forget-it security solution for themselves, or for a loved one.
3. Avast Free Antivirus
Nearly a free suite.Pros: Loaded with extra features; highly customizable; VPN client
Cons: So-so malware protection; heavy performance hit; possible privacy concerns
The malware protection in Avast Free Antivirus is a peg down from the top, but it's got the best assortment of extra goodies for a free antivirus program, including a password manager, a hardened browser and a network scanner. The program is also very customizable and offers limited access to Avast's VPN service. However, it caused a pretty heavy system load in our testing.
4. Microsoft Windows Defender
Finally good enough.Pros: Good malware protection; built into Windows; small performance impact
Microsoft's built-in antivirus software has finally reached the big leagues. Windows Defender won't beat Bitdefender or Kaspersky in malware protection, but it holds its own against other free antivirus products while delivering a small system-performance impact and a surprising number of extra features, including parental controls and protection for all browsers. For the first time, we can recommend using Windows Defender as your primary antivirus solution.
5. AVG AntiVirus Free
Not enough oomph.Pros: Small performance impact; file shredder; customizable
Cons: Middling malware protection; few extra features; possible privacy issues
AVG shares Avast's decent if unspectacular malware-detection engine while having a much lighter system-performance impact. But AVG AntiVirus Free has far fewer useful extra features than Avast Free Antivirus. The good news is that AVG's wide range of customization options and its file shredder are still available; the bad news is that there's no compelling reason to pick AVG over Windows Defender.
6. Avira Free Antivirus
Not what it once was.Pros: Highly customizable; lots of add-ons; firewall manager
Cons: Mediocre malware protection; most extra features are trialware; heavy performance impact
Avira Free Antivirus was the best free antivirus option just a few years ago, before Bitdefender and Kaspersky jumped into the ring and Avast, AVG and Windows Defender raised their game. Now Avira's malware protection is in the middle of the pack. Its numerous extra features are mostly just teases for paid services, and its system-performance impact is remarkably heavy. We do like that it's still got a wide range of customization options.
7. Panda Free Antivirus
Has its ups and downs.Pros: Very customizable; moderate performance impact; VPN client
Cons: Spotty malware protection; no opting out of data collection
Panda doesn't take part in every lab test whose results we use, so its malware protection is a bit of an enigma. We liked Panda Free Antivirus' high degree of customization options and its appealing interface. We didn't like the constant ads for other Panda products, the attempts to hijack your web browser, and the fact that unlike every other antivirus company, Panda won't let you opt out of automatic system-data collection.
Malwarebytes Anti-Malware Free
Essential side piece.Pros: Complements antivirus software; removes adware, other unwanted software
Cons: Installs trialware of paid version; manual definition updates
Malwarebytes Anti-Malware Free is not antivirus software. It's more of a malware-removal tool. Malwarebytes Anti-Malware Free can't protect a PC from infection, but it does an excellent job of cleaning out malware that's already on your system. Plus, it doesn't interfere with any antivirus software that's already installed. We recommend Malwarebytes Anti-Malware Free as a complement to any antivirus program.