Maybe you think your computer doesn't need antivirus protection. You don't keep important information on it, you just use it to surf the web and watch funny cat videos, so why spend money on an antivirus utility? Then one day you turn the PC on and find that it's been locked by ransomware—no cat videos for you! Or worse, your ISP shuts down your Internet connection because your home network has become a command-and-control server for GameOver Zeus or another distributed botnet. You don't have to spend money on a commercial antivirus utility to head off these and other dire scenarios. Free antivirus utilities do everything their commercial cousins do, and the best free ones do it better than many for-pay competitors. We've rounded up a collection of totally free antivirus products that should serve you well.
Yes, it's true that Windows 8 and Windows 10 have antivirus built right in, but in our tests and most independent lab tests, Windows Defender just doesn't do the job. Antivirus protection in earlier Windows versions is even less comprehensive.
Your antivirus should definitely have the ability to root out existing malware, but its ongoing task is to prevent ransomware, botnets, and other types of nasty programs from getting a foothold. All of the antivirus programs in this collection offer real-time protection against malware attack. Some take the fight upstream, working hard to ensure you never even browse to a malware-hosting site or get fooled into turning over your credentials to a phishing site
Independent Lab Antivirus Test Results
Around the world, researchers at independent antivirus testing labs spend their days putting antivirus tools to the test. Some of these labs regularly release public reports on their findings. I follow six such labs closely: AV-Comparatives,AV-Test Institute, Dennis Technology Labs, ICSA Labs, Virus Bulletin, and West Coast Labs.
Security companies typically pay for the privilege of being included in testing. In return, the labs supply them with detailed reports that can help improve their products. The number of labs that include a particular vendor serves as a measure of significance. In each case, the lab considered the product important enough to test, and the vendor felt the price was worthwhile. The labs don't necessarily test a vendor's free product, but most vendors pack full protection into the free product, enhancing premium versions with additional features. I've worked out a system for aggregating lab results, yielding a lab score from 0 to 5, or N/A if there just isn't enough data.
PCMag Antivirus Test Results
In addition to carefully perusing results from the independent labs, I also run my own hands-on malware blocking test. I expose each antivirus to a collection of malware samples, including a variety of different malware types, and note its reaction. Typically the antivirus will wipe out most of the samples on sight, and detect some of the remaining ones when I try to launch them. I derive a malware blocking score from 0 to 10 points based on how thoroughly the antivirus protects the test system from these samples.
Since I use the same samples month after month, the malware-blocking test definitely doesn't measure a product's ability to detect brand-new threats. In a separate test, I attempt to download malware from 100 very new malicious URLs, typically less than a day old. I note whether the antivirus blocked all access to the URL, wiped out the malicious payload during download, or did nothing.
Just about every antivirus product scans files on access to make sure malware can't launch, and also scans the entire system on demand, or on a schedule you set. The one exception in the current collection is a tool aimed very specifically at detecting attempts to exploit vulnerabilities in the operating system or applications. That tool, Malwarebytes Anti-Exploit Free, is designed for use in conjunction with a regular antivirus.
Blocking all access to malware-hosting URLs is a nice way to avoid trouble. Many products extend that protection to also steer users away from fraudulent websites, phishing sites that try to steal login credentials for financial sites and other sensitive sites. A few rate links in search results, flagging any dangerous or iffy ones.
Behavior-based detection, a feature of some antivirus products, is a two-edged sword. On the one hand, it can detect malware that's never been seen before. On the other hand, if it's not done right, it can baffle the user with messages about perfectly legitimate programs.
One easy way to keep your PC protected is to install all security updates, both for Windows and for browsers and other popular applications. Starting with Windows 10, Windows updates aren't optional for consumers , but there are plenty of security holes in popular apps and add-ons. Scanning for vulnerabilities in the form of missing updates is a feature most often found in commercial antivirus products, but it does turn up in some free ones. Other useful bonus features include preventing USB-based malware attacks, scanning for router weaknesses, and cleaning up traces of browsing history. In the chart above you can see which products include these useful features.
What's Not Here
This article reports only on free antivirus products that received at least a good rating in our reviews—three stars or better. Among those that didn't make the cut is Microsoft Security Essentials / Windows Defender. All of the independent labs I follow do include Microsoft in testing, but most use it as a baseline. If a product can't do better than the baseline, it's got real problems. My aggregate lab score for Microsoft comes to zero stars. Zero stars! In addition, it performed poorly in all of my hands-on tests.
There are also numerous free antivirus utilities that work solely to clean up existing malware infestations. You bring out these cleanup-only tools when you have a nasty malware infestation. When the problem's gone, they have no further use, since they offer no ongoing protection. Our Editors' Choice in this category is Malwarebytes Anti-Malware 2.0, and it's definitely one you should try if you've got a malware problem. But since they're free, you can keep trying others if the first one doesn't do the job. When the scare is over, you'll need a full-blown antivirus for ongoing protection.
Our current Editors' Choice for free antivirus utility is Panda Free Antivirus 2016. Panda gets very good scores from the independent labs, and in our own tests as well. It also includes some useful bonus features. Bitdefender Antivirus Free Edition (2014) is good, too, though Bitdefender's commercial edition is significantly better. If you do have a little cash in your budget for security, the best commercial antivirus products do tend to offer more and better protection. As always, given that these products are free, you can shop around, try several to see which suits you best.
Panda Free Antivirus 2016
While Panda Free Antivirus doesn't outperform the very best commercial antivirus tools, it's way better than the rank and file of for-pay solutions. It remains our Editors' Choice for no-fee antivirus. Read the full review ››
Bitdefender Antivirus Free Edition (2014)
You'll hardly know Bitdefender Antivirus Free Edition (2014) is present on your system, unless it quashes a problem. Its tiny main window and unobtrusive style are great if you want a strong, silent, and free antivirus solution. Read the full review ››
Malwarebytes Anti-Exploit Free
Malwarebytes Anti-Exploit Free shields your browsers against exploit attacks, even never-before-seen zero-day attacks. Give this unusual, free security tool a try. Read the full review ››
Ad-Aware Free Antivirus+ 11
The folks at Lavasoft gave Ad-Aware Free Antivirus+ 11 a total user-interface makeover and a new antivirus engine partner. The user interface is truly pleasing, a nice change. However, the product lost a little ground in malware blocking. Read the full review ››
Avast Free Antivirus 2015
The new home router security check in Avast Free Antivirus 2015 is brilliant; this area has been totally overlooked by most vendors. However, the product's central antivirus protection is just average. Read the full review ››
Qihoo 360 Total Security Essential
Qihoo 360 Total Security Essential scores very well in our hands-on tests and in tests by independent labs, but only if you change its default configuration to enable all antivirus engines. Read the full review ››
Comodo Antivirus 8
Comodo Antivirus 8 offers decent antivirus protection and a whole raft of advanced security features. However, those advanced features are probably too complex for the average user. Read the full review ››