The Best Free Antivirus Protection for 2021

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The Best Free Antivirus Protection for 2021

Windows Defender is improving, but you still shouldn't rely on it by itself. That doesn’t mean you have to pay extra, though! We’ve tested the top free antivirus apps so you can protect your PC for free.

Best For Best for Excellent Lab Test Scores

Kaspersky Security Cloud Free
Kaspersky Security Cloud Free Read Kaspersky Security Cloud Free Review

Best For Best For Wealth of Bonus Features

Avast Free Antivirus
Avast Free Antivirus Read Avast Free Antivirus Review

Best For Best For Few-Frills Protection

AVG AntiVirus Free
AVG AntiVirus Free Read AVG AntiVirus Free Review

Bitdefender Antivirus Free Edition
Bitdefender Antivirus Free Edition Read Bitdefender Antivirus Free Edition (2017) Review

Best For Best for Managed Family Protection

Sophos Home Free
Sophos Home Free Read Sophos Home Free Review

Avira Antivirus
Avira Antivirus Read Avira Antivirus Review

Best For Best for Many Security Components

Avira Free Security
Avira Free Security Read Avira Free Security Review

Microsoft Windows Defender Security Center
Microsoft Windows Defender Security Center Read Microsoft Windows Defender Security Center Review Review

Best For Best for Brand Loyalists

Adaware Antivirus Free
Adaware Antivirus Free Read Adaware Antivirus Free Review

Check Point ZoneAlarm Free Antivirus+
Check Point ZoneAlarm Free Antivirus+ Read Check Point ZoneAlarm Free Antivirus+ Review

Best For Best for Utility Collectors

360 Total Security
360 Total Security Read Qihoo 360 Total Security Review

Free Malware, Spyware, and Adware Protection

Back in the day, some bars would offer a free lunch to anyone buying drinks. Of course, it wasn’t really free; you paid for it in the price of your drinks. Wiser souls would remark, “There ain’t no such thing as a free lunch.” Well, when it comes to antivirus software, it turns out TANSTAAFL isn’t necessarily so. You can actually get effective protection without paying a dime, or buying a drink. If you’re one of those rare folks whose computers are naked to the world, unprotected by antivirus, get a clue! Install a free antivirus right away. If it doesn’t suit you after a while, switch to another one. We’ve tested dozens of free and commercial antivirus tools to help you with that choice.

Your antivirus should definitely have the ability to root out existing malware, but its ongoing task is to prevent ransomware, botnets, Trojans, and other types of nasty programs from getting a foothold. All of the antivirus programs in this collection offer real-time malware protection. Some take the fight to the browser, 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.

The Best Antivirus Deals This Week

Free Antivirus vs. Paid Antivirus

If free antivirus tools are so great, why should anybody pay? For one thing, quite a few of these products are free only for noncommercial use; if you want to protect your business, you must pony up for the paid edition. At that point, you should probably consider upgrading to a full security suite. After all, it's your business's security on the line.

Even for personal use, most for-pay antivirus tools offer more than their free counterparts—sometimes a lot more. For example, the paid editions of Adaware and ZoneAlarm add protection against malicious and fraudulent websites that the free versions lack. And Panda reserves quite a few features for paying customers, among them firewall protection, application control, cross-platform support, and detection of insecure Wi-Fi connections.

In addition, many companies don't offer full-scale tech support for users of the free edition. The first time you need extra help digging a particularly stubborn piece of malware out of your system, you might regret the lack of support.

Independent Antivirus Lab 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. We follow four such labs closely: AV-Comparatives, MRG-Effitas, SE Labs, and AV-Test Institute. We also take note of whether vendors have contracted for certification by ICSA Labs 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.

We Test Malware Protection

In addition to carefully perusing results from the independent labs, we also run our own hands-on malware protection test. We 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 we try to launch them. We derive a malware blocking score from 0 to 10 points based on how thoroughly the antivirus protects the test system from these samples.

Since we use the same samples month after month, the malware-blocking test doesn't measure a product's ability to detect brand-new threats. In a separate test, we attempt to download malware from 100 very new malicious URLs supplied by London-based testing lab MRG-Effitas, typically less than a few days old. We note whether the antivirus blocked all access to the URL, wiped out the malicious payload during download, or did nothing. Sophos Home Free managed 100 percent protection in its latest test, as did McAfee and Vipre.

If you're interested in learning more about our testing techniques, you're welcome to read more about how we test security software.

Useful Features

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. Once that cleaning and scheduling is done, blocking all access to malware-hosting URLs is another good 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.

Any antivirus should eliminate spyware along with other types of malware, but some products include features designed specifically for spyware protection. Features like encryption to protect your sensitive data and webcam control to prevent remote peeping typically show up in commercial products, not free ones. But some free products include features like a simple on-screen keyboard to foil keyloggers.

One easy way to keep your PC protected is to install all security updates, both for Windows and for browsers and other popular applications. Windows 10 makes it easier than ever to stay up to date, but there are plenty of security holes in older Windows versions, in popular apps, and in 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. In the list below you can see which products include these useful features.

What's Not Here?

Previous editions of this article reported only on free antivirus products that received at least a good rating in our reviews—three stars or better. One of the listed products lost ground recently. Poor performance in testing brought Qihoo 360 down to 2.5 stars. We've kept it in the roundup, so you can see how it stacks up, but we don't recommend it.

Microsoft Windows Defender Security Center moved up to a three-star score a few years ago; it's now at 3.5 stars. Yes, it's more of a Windows component than a free product. Yes, the very best free antivirus utilities offer many more layers of protection. But Windows Defender protects everyone who can't be bothered to install a third-party antivirus tool.

Several free utilities devoted entirely to ransomware protection have come on the scene in the last few years. Alas, several of those have fallen by the wayside, among them Bitdefender Anti-Ransomware, Cybereason RansomFree, and CyberSight RansomStopper. In any case, these are useful companion products, but they don't do the job of a full-scale antivirus utility.

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 problem. When the malware's gone, they have no further use, since they offer no ongoing protection. Our favorite in this category is Malwarebytes Anti-Malware, and it's 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.

Which Free Antivirus Is Best?

Our current Editors' Choice picks for free antivirus utility are Avast Free Antivirus and Kaspersky Security Cloud Free. Both appear in lab reports from all four labs we follow. Kaspersky earned near-perfect scores, and Avast came close. We did strip Avast's Editors' Choice award last year after a privacy problem with sharing of user data. That problem was solved, so we've taken Avast out of the penalty box. If you do have a little cash in your budget for security, the best paid antivirus software does offer more and better protection. If not, try a few of these free tools and see which one you like best.

Worried you might already be infected? Check out our article on the signs you have malware.

Our Pick
Rating
Website Rating
Vulnerability Scan
Vaccination
Recover Files
Ransomware Behavior Detection
Protection Type
Prevent File Modification
Prevent All File Access
Phishing Protection
On-Demand Malware Scan
On-Access Malware Scan
Malicious URL Blocking
Firewall
Behavior-Based Detection
Kaspersky Security Cloud Free
Kaspersky Security Cloud Free
Editors' Choice
Excellent (4.5)
Review
Antivirus
Avast Free Antivirus
Avast Free Antivirus
Editors' Choice
Excellent (4.5)
Review
AVG AntiVirus Free
AVG AntiVirus Free
Excellent (4.0)
Review
Bitdefender Antivirus Free Edition
Bitdefender Antivirus Free Edition
Excellent (4.0)
Review
Sophos Home Free
Sophos Home Free
Excellent (4.0)
Review
Avira Antivirus
Avira Antivirus
Good (3.5)
Review
Avira Free Security
Avira Free Security
Good (3.5)
Review
Microsoft Windows Defender Security Center
Microsoft Windows Defender Security Center
Good (3.5)
Review
Adaware Antivirus Free
Adaware Antivirus Free
Fair (2.5)
Review
Check Point ZoneAlarm Free Antivirus+
Check Point ZoneAlarm Free Antivirus+
Good (3.0)
Review

About Neil J. Rubenking