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.

Our 10 Top Picks

Best for Wealth of Bonus Features

Avast Free Antivirus

Best for Excellent Lab Test Scores

Kaspersky Security Cloud Free

Best for Few-Frills Protection

AVG AntiVirus Free

Best for Set-and-Forget Protection

Bitdefender Antivirus Free Edition

Best for Managed Family Protection

Sophos Home Free

Best for Many Security Components

Avira Free Security

Best for Windows Diehards

Microsoft Windows Defender Security Center

Best for Personal Firewall Fans

Check Point ZoneAlarm Free Antivirus+

Best for No-Frills Protection

Adaware Antivirus Free

Best for Managed Family Protection

Qihoo 360 Total Security

Compare Specs The Best Free Antivirus Protection for 2021

Free Malware, Spyware, and Adware Protection

Some people optimistically say the best things in life are free, while others dourly contend that you only get what you pay for. When it comes to antivirus software, it turns out that the rosier viewpoint is correct. You can get surprisingly capable protection without having to pay anything. So, what are you waiting for? Install free protection immediately! Once it’s up and running, take your time reading this article and our reviews. If you feel a different free antivirus would suite you better, switching doesn’t cost you anything. We’ve tested both free and commercial antivirus tools to help you choose.

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.

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, ZoneAlarm’s paid edition adds protection against malicious and fraudulent websites that the free version lacks. 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.

The Best Antivirus Deals This Week*

*Deals are selected by our partner, TechBargains

• McAfee Total Protection — $69.99 for 10-Devices on a 2-Year Plan(List Price $239.98)
• Norton AntiVirus Plus — $19.99 for 1-Device on 1-Year Plan(List Price $59.99)
• Bitdefender Total Security — $39.98 for 5-Devices on 1-Year Plan(List Price $89.99)
• Webroot SecureAnywhere — $18.99 for 1-Device on 1-Year Plan(List Price $39.99)
• VIPRE Ultimate Security — $39.99 for 5-Devices on 1-Year Plan(List Price $139.99)

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. A couple of the listed products lost ground recently. Poor performance in testing brought Adaware and Qihoo 360 down to 2.5 stars. We’ve kept them in the roundup, so you can see how they stack up, but we don’t recommend them.

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.

The Best Antivirus Protection for 2021

Antivirus software is critical for every PC. Without it, you risk losing your personal information, your files, and even the cash from your bank account. We’ve tested more than 40 utilities to help you pick the best antivirus protection for your computers.

Our 13 Top Picks

Best for Multi-Device Households

McAfee AntiVirus Plus

Best for Single Desktop Protection

Norton AntiVirus Plus

Best for Excellent Lab Test Scores

Kaspersky Anti-Virus

Best for Wealth of Bonus Features

Bitdefender Antivirus Plus

Best for Small Size and Speedy Scan

Webroot SecureAnywhere AntiVirus

Best for Techies

ESET NOD32 Antivirus

Best for Speedy Scanning

Malwarebytes Premium

Best for Thrifty Users

Sophos Home Premium

Best for Single Desktop Protection

Trend Micro Antivirus+ Security

Best for No-Frills Protection

F-Secure Anti-Virus

Best For Machine Learning

Cylance Smart Antivirus

Best for Breadth of Features

G Data Antivirus

Best For Remote Management

Emsisoft Anti-Malware

Compare Specs The Best Antivirus Protection for 2021

Malware, Spyware, and Adware Protection

“I don’t need an antivirus program,” you say. “I don’t have anything important on my computer. I just share social media posts with my friends and watch cat videos.” Let’s suppose that’s true, that you’re not forgetting the occasional login to your bank, or to your email account. You could still find your social media accounts take over by malware. A bot could enlist your computer into a zombie army to spew spam or participate in a DDoS attack, and those extra tasks could make your cat videos laggy. Ransomware could lock up your computer entirely—no more social posts for you! In truth, you probably do use your computer for important activities, activities that malware could disrupt. You need antivirus protection that’s up to date. If yours is outdated or absent, don’t worry. We’ve put more than 40 antivirus tools through testing and evaluation, so you can pick the one that’s best for you.

We call it antivirus, but in truth it’s unlikely you’ll get hit with an actual computer virus. Malware these days is about making money, and there’s no easy way to cash in on spreading a virus. Ransomware and data-stealing Trojans are much more common, as are bots that let the bot-herder rent out your computer for nefarious purposes. Modern antivirus utilities handle Trojans, rootkits, spyware, adware, ransomware, and more. As noted, PCMag has reviewed more than 40 different commercial antivirus utilities, and that’s not even counting the many free antivirus tools. Out of that extensive field we’ve named four Editors’ Choice products, honored others with a four-star rating, and bestowed 3.5 stars on several more. If you have malware, one of the products listed in this article should take care of the problem.

Some nonstandard commercial antivirus utilities proved effective enough to earn an excellent four-star rating alongside their more traditional counterparts. VoodooSoft VoodooShield bases its protection on suppressing all unknown programs while the computer is in a vulnerable state, such as when it’s connected to the internet, and also acts to detect known malware. The Kure resets the computer to a known safe state on every reboot, thereby eliminating any malware. These are interesting approaches, but not directly comparable with traditional antivirus tools.

The Best Antivirus Deals This Week*

*Deals are selected by our partner, TechBargains

• McAfee Total Protection — $69.99 for 10-Devices on a 2-Year Plan(List Price $239.98)
• Norton AntiVirus Plus — $19.99 for 1-Device on 1-Year Plan(List Price $59.99)
• Bitdefender Total Security — $39.98 for 5-Devices on 1-Year Plan(List Price $89.99)
• Webroot SecureAnywhere — $18.99 for 1-Device on 1-Year Plan(List Price $39.99)
• VIPRE Ultimate Security — $39.99 for 5-Devices on 1-Year Plan(List Price $139.99)

These commercial products offer protection beyond the antivirus built into Windows 10; the best free antivirus utilities also offer more than Windows does. However, Microsoft Windows Defender Security Center is looking better and better lately, with some very good scores from independent testing labs. The combination of good lab scores and a great score in our hands-on malware protection test was enough to bring it up to 3.5 stars. It doesn’t appear in this roundup of commercial antivirus products, naturally.

Listen to the Antivirus Testing Labs

We take the results reported by independent antivirus testing labs very seriously. The simple fact that a company’s product shows up in the results is a vote of confidence, of sorts. It means the lab considered the product significant, and the company felt the cost of testing was worthwhile. Of course, high scores in the tests are also important.

We follow four labs that regularly release detailed reports: SE Labs, AV-Test Institute, MRG-Effitas, and AV-Comparatives. We’ve devised a system for aggregating their results to yield a rating from 0 to 10.

We Test Malware, Spyware, and Adware Defenses

We also subject every product to our own hands-on test of malware protection, in part to get a feeling for how the product works. Depending on how thoroughly the product prevents malware installation, it can earn up to 10 points for malware protection.

Our malware protection test necessarily uses the same set of samples for months. To check a product’s handling of brand-new malware, we test each product using 100 extremely new malware-hosting URLs supplied by MRG-Effitas, noting what percentage of them it blocked. Products get equal credit for preventing all access to the malicious URL and for wiping out the malware during download.

Some products earn stellar ratings from the independent labs, yet don’t fare as well in our hands-on tests. In such cases, we defer to the labs, as they bring significantly greater resources to their testing. Want to know more? You can dig in for a detailed description of how we test security software.

Multilayered Malware Protection

Antivirus products distinguish themselves by going beyond the basics of on-demand scanning and real-time malware protection. Some rate URLs that you visit or that show up in search results, using a red-yellow-green color-coding system. Some actively block processes on your system from connecting with known malware-hosting URLs or with fraudulent (phishing) pages.

Software has flaws, and sometimes those flaws affect your security. Prudent users keep Windows and all programs patched, fixing those flaws as soon as possible. The vulnerability scan offered by some antivirus products can verify that all necessary patches are present, and even apply any that are missing.

Spyware comes in many forms, from hidden programs that log your every keystroke to Trojans that masquerade as valid programs while mining your personal data. Any antivirus should handle spyware, along with all other types of malware, but some include specialized components devoted to spyware protection.

You expect an antivirus to identify and eliminate bad programs, and to leave good programs alone. What about unknowns, programs it can’t identify as good or bad? Behavior-based detection can, in theory, protect you against malware that’s so new researchers have never encountered it. However, this isn’t always an unmixed blessing. It’s not uncommon for behavioral detection systems to flag many innocuous behaviors performed by legitimate programs.

Whitelisting is another approach to the problem of unknown programs. A whitelist-based security system only allows known good programs to run. Unknowns are banned. This mode doesn’t suit all situations, but it can be useful. Sandboxing lets unknown programs run, but it isolates them from full access to your system, so they can’t do permanent harm. These various added layers serve to enhance your protection against malware.

Firewalls, Ransomware Protection, and More

Firewalls and spam filtering aren’t common antivirus features, but some of our top products include them as bonuses. In fact, some of these antivirus products are more feature-packed than certain products sold as security suites.

Among the other bonus features you’ll find are secure browsers for financial transactions, secure deletion of sensitive files, wiping traces of computer and browsing history, credit monitoring, virtual keyboard to foil keyloggers, cross-platform protection, and more. And of course, we’ve already mentioned sandboxing, vulnerability scanning, and application whitelisting.

We’re seeing more and more antivirus products adding modules specifically designed for ransomware protection. Some work by preventing unauthorized changes to protected files. Others keep watch for suspicious behaviors that suggest malware. Some even aim to reverse the damage. Given the growth of this scourge, any added protection is beneficial.

Beyond Antivirus: VPN

Your antivirus utility works in the background to keep out any faint possibility of infestation by malware, but its abilities don’t extend beyond the bounds of your computer. When you connect to the wild and wooly internet, you risk the possibility that your data could be compromised in transit. Sticking to HTTPS websites when possible can help, but for full protection of your data in transit you should install a Virtual Private Network, or VPN. This component is important enough that we’re starting to see it as a bonus feature in some antivirus tools.

What’s the Best Malware Protection?

Which antivirus should you choose? You have a wealth of options. Kaspersky Anti-Virus and Bitdefender Antivirus Plus routinely take perfect or near-perfect scores from the independent antivirus testing labs. A single subscription for McAfee AntiVirus Plus lets you install protection on all your Windows, Android, Mac OS, and iOS devices. And its unusual behavior-based detection technology means Webroot SecureAnywhere Antivirus is the tiniest antivirus around. We’ve named these four Editors’ Choice for commercial antivirus, but they’re not the only products worth consideration. Read the reviews of our top-rated products, and then make your own decision.

Editors’ Note: We are aware of the allegations of Kaspersky Labs’ inappropriate ties to the Russian government. Until we see some actual proof of these allegations, we will treat them as unproven, and continue to recommend Kaspersky’s security products as long as their performance continues to merit our endorsement.